-Passengers Weight: smaller cart rides are more impacted by the mass of passengers, the additional mass can almost double the total mass of the cart, therefore, it can increase the momentum on the rollercoaster.

-Wheel Types: Common wheels that are made of a harder material (nylon) can increase speed in colder temperature, and common softer wheels (polyurethane) can slow down the roller coaster in warmer temperature due to friction.

-Weather and Paint: Rain can lessen the friction of the cart and the rail. Wind/Air resistance can slow down or speed up the cart. Thick layers of paint can create additional friction.

Next Question: Why might friction play an important role on the pros and cons of a roller coasters ride, because due to the negative impacts of rollercoasters decreasing in speed due to friction, can friction have a positive impact? How?

The effects of gravitational force are considered in roller coaster designs to make it a thrilling experience. There are multiple types of g-force that are in action during the ride.

Linear g-force

-forward and backward directions

-result of the increase/decrease of speed

-e.g. launch time as the train accelerates, the force pushes riders back and they move with the train in a straight direction

Positive and Negative g-force

-up and down, during changes in elevation (valleys, upward tracks)

-e.g. at the bottom of a drop, riders are pushed against their seats and feel heavier

-weak g-force is known as floater airtime and gives a feeling of weightlessness

-strong g-force is called ejector airtime and causes riders to rise up and makes the ride aggressive at the tops of hills

Lateral g-force

-left and right directions

-e.g. wild mouse roller coasters with flat sudden turns produce high lateral force

-extreme ones can be uncomfortable and are reduced by banking the track and converting the force into positive

Sustained forces

-sustained forces that last for several seconds can affect riders more than spikes in multiple directions

-long sweeping bends make it hard for the body to pump blood to the head, but it isn't long enough to be harmful

Next question: Gravitational force is considered greatly in the design and movement of roller coasters, what other forces need to be accounted for?

Thus, tear drop shaped loops called clothoid loops are used. Alongside friction and air resistance, the roller coaster experiences gravity and normal force which is always perpendicular to the track. At the bottom of the loop, the normal force pushes the car upwards while at the top, the normal force is directed downwards. The normal force must supply enough force to result in a net inward force. Clothoid loops allow cars to enter at high speeds but due to the large radius, the normal forces don’t exceed 3.5 G, allowing the car and its passengers to safely make it through the loop. Since the radius of curvature is greater at the bottom and sides but less at the top, this reduces the side acceleration and prevents the body from experiencing a jerk.

Next Question: Normal force and gravity play a key role in roller coasters but how do friction and air resistance impact the cars and the passengers in them?

• Like a train, roller coasters run on a track that follows a certain path, but unlike a train, a roller coaster cart has no engine or power system that keeps it going. It is actually powered completely by gravitational force and momentum. For a coaster to gain this momentum, it first has to make its way up the hill, it does this with something called chain dogs that latch onto a large chain connected into a loop at the top and bottom of the hill, and like a large conveyor belt, it brings what is at the bottom to the top of the hill. This is the most common way for roller masters to get up the large hill at the beginning of the ride, but some rather use a catapult launch to get the riders up the hill. Instead of slowly creating more and more potential energy that will be converted into kinetic energy, the catapult launch instead creates a significant amount of energy immediately. Once the chain dogs unlatch from the chain at the top of the hill, gravity works it's part and creates lots of momentum that will carry the cart throughout the coaster until it gets to the end and meets the braking system.

How are roller coasters designed to navigate the track safely at high speeds?

• To properly construct a roller coaster, it is important to consider all the components that go into it to make it safe to ride. The first component that is instrumental is a roller coasters safety would be the brakes; the brakes are a computer operated hydraulic system built into the track, so that when the roller coaster reaches a certain point of the ride. There are a series of clamps positioned on the track so that when the roller coaster reaches this point, the hydraulic system will close the clamps on metal fins running under the cart creating enough fiction to stop the train. There are a few series of these positioned around the track for safety reasons in the chance an emergency stop would need to be made.

• Another important factor that goes into designing a safe roller coaster would be the safety restraints. These act against the forces that are moving the passengers while on the ride. When the train stops, the passengers will be thrust forward and the safety restraints will stop the riders from being thrown out of the train. They also act when the passengers are being lifted from their seats due to the acceleration down the hill, the safety restraints stop people from flying out of their seats.

• Centripetal force is what makes sure that roller coasters remain on the track while navigating curves in the track. It is also the force that is felt in a car when turning a corner. This must always be considered when building a roller coaster as it has a large part in keeping the cart on the track.

What aspects of weather conditions, passengers, durability and overall enjoyment are considered?

• Some weather conditions that impact a roller coaster's function would be wind resistance, temperature, and rain. With too much wind resistance, a roller coaster can decelerate up to 30 miles per hour. Light rain has little to no impact but heavy rains can cause sensors that control the hydraulic brakes to malfunction, and when there is lightning, a roller coaster can act as a lightning rod causing it to become very unsafe. Temperature also can have an impact on a ride as the wheels are made of a material that can slightly harden or soften due to temperatures and this can impact the rolling friction, and speeds of the coaster.

• Passengers can impact a coaster through their mass. If the mass of passengers is larger than that of the masses that were tested with, it wont cause the coaster to go faster or slower, but it will make it harder to slow down, because it will be a heavier object with the same amount of speed, thus making it harder to slow down.

• Roller coasters must be durable as they are typically outside and can be subject to all natural forces such as wind, rain, UV, etc. If a roller coaster is not durable enough it could malfunction or break, causing it be be unsafe.

  
  

NEXT QUESTION: How might passengers be impacted if a roller coaster is designed improperly? What forces could have negative consequences if too extreme?

Nerve Electrical Properties. Changes in nerve activity in response to RF radiation, especially in controlled laboratory conditions with isolated nerve preparations (ex. Aplysia neurons, frog sciatic nerves). At high power levels (specific absorption rate, SAR, over 5 W/kg), changes in nerve firing rates and refractory periods were found. This is thought to be due to the heating, or “invisible forces of friction”. 

Blood-Brain Barrier: Non thermal RF/EMF radiation can affect the blood-brain barrier’s permeability, linked to higher SAR levels (above 2 w/kg) that cause local heating (forces acted upon each other). 

Low-Frequency Electric and Magnetic Fields: Extremely low-frequency (ELF) electric and magnetic field / forces have been shown to influence system activity only at high intensities (0.1-1.0 A/m^2 or more). These effects include neuromuscular stimulation, and EEG (on occasion). 

• Summary: Electromagnetic forces, particularly RF and ELF fields, can impact the nervous system, but the effects are also largely dependent on intensity, frequency, and the presence of thermal effects. High-intensity fields are more likely to produce noticeable changes, while low-intensity, nonthermal fields, especially those modulated at specific frequencies, may cause subtle alteration in cellular and brain activity, though these are still not found to be linked to significant health issues- are still considered to be negative impacts and implications of the MRI and fMRI technologies.

• NEXT QUESTION: How do varying intensities and frequencies of electromagnetic forces, including RF and ELF fields, differentially affect the molecular and cellular structures of the nervous system, and what long term implications might these forces have on tissue integrity, neurological function and overall health in individuals undergoing repeated MRI or fMRI procedures?

-opposes the motion through the air, generated by the difference of velocity between the moving train and the air passing by

-drag depends on velocity and acts perpendicular to the surface-the surface area of the train in important to consider as the larger the area, the more drag

-the shape of the train has to be sleek, similar to cars, to prevent air resistance

-increased speed and bigger surface area result in more resistance

-light trains will be more noticeably impacted by drag

-the speed and direction of the wind also impacts the speed of the roller coaster, wind moving against one side of the train poses a risk by stalling its movement, which is why strong winds might force parks to be closed temporarily

Friction

-friction is independent to the velocity and acts tangent to surfaces

-it often occurs between the wheels and track of a roller coaster and converts some kinetic energy into heat, which impacts the speed

-wheel bearing clearance: the assembly of the wheels’ internal parts can reduce friction and heat loss, it is important to have the wheels perfectly straight and aligned to prevent any extra friction against surfaces

-the amount/type of grease on the wheels is also important

-too little grease speeds up the train while too much slows it down

-the track has to be lubricated to reduce the amount of friction which also prevents the track and wheels from wearing down too fast

-rolling resistance/friction/drag is the force resisting motion when something rolls on a surface and is why the material should be considered when it comes to the speed of roller coasters

Next question: How are roller coasters designed to stop the momentum safely and efficiently? What forces are used to accomplish this?

• The track layout, the speed of the coaster, and the size of the drops all affect the G-forces that riders experience. For example, a roller coaster with a steep drop will create more negative G-forces than a roller coaster with a gradual drop. 

• Positive g-forces are experienced when an object is accelerating in the same direction as gravity, such as when a roller coaster goes up a hill.

• Negative g-forces are experienced when an object is accelerating in the opposite direction to gravity, such as when a roller coaster goes down a hill.

Rollercoasters’ limitations and restrictions to protect passengers: High G-force can cause injury or death if sustained for too long

• Safety Features: brakes, to control g-forces

• Regular maintenance to ensure safety

• Height and Weight restrictions

• Restraints and Harnesses

• Minimizing sudden changes of direction or speed or drops

• Weight distribution (lower centre of gravity can reduce lateral g-force during sharp turns)

• Shape and height of airtime hills

Effects of G-force on the human body:

• Blood vessels can burst (in the retina/eye which can cause permanent damage)

• Compression of lungs (oxygen deprivation)

• Fainting (blood pools to lower body which deprives brain of oxygen, which can cause permanent damage)

Next Question:

How else can passengers become negatively impacted by g-forces or other factors/forces that can come from roller coasters?

• An MRI Machine, also known as magnetic resonance imaging is a tool used by doctors to diagnose internal issues that cannot be seen in an x-ray, ultrasound, or CT scan. By passing an electric current through coiled wires to create a magnetic field inside your body, then sending radio waves through your body, a computer then receives all the information from the radio waves that bounce off or go through different materials in your body and converts these into an image of inside the human body.

• An MRI scan has many positives when it comes to use, such as: providing better soft tissue contrast, help diagnose countless conditions and diseases, a primarily safe process, etc. Since a person in an MRI machine is subject to a very strong magnetic field, and radio frequent energy, which both carry specific safety concerns.

  IMPACT:

• Magnetic fields that change with time like those in an MRI can create loud knocking noises due to the magnetic coils inside the machine colliding in turn which results in the making of the magnetic field. These noises can reach up to 100 decibels so patients going through an MRI machine have to wear ear protection - they can even listen to music.

• The radio frequency energy used during an MRI scan can also cause the body to heat up, and his is much more abundant during a longer scan

  ELECTROMAGNETIC FORCES:

• The electromagnetic spectrum shows the full range of electromagnetic radiation organized by strength/frequency. The longer the wavelength, the lower energy a type of electromagnetic force has.

  • Since an MRI machine utilizes radio waves to receive imaging from inside the body, patients will be exposed to electromagnetic energy (radio waves are on the left side of the electromagnetic spectrum, meaning it has the longest wavelengths and lowest energy). If a person is exposed to high levels of EMF's for too long, there can be many health effects including:

  • Disruption in the structures of human tissues. Due to the absorption of too much electromagnetic energy, the electric current inside of the human body can be thrown off and this can impact the electricity used by our nervous system to relay sensation around the body, along with basic human functions like speaking and thinking as the communication is signals transmitted by human energy/natural electric current in the body.

  • Damage to human cells and DNA

  • Lower EMF's are said to induce things like stress, tiredness, lack of concentration, anxiety, decreased learning potential, and impairment of cognitive functions

  CONCLUSION:

• Since MRI machines use a strong changing magnetic field, along with radio frequency waves to obtain imaging of the human body, there can be a few risks associated with this. There a are few effects that are directly connected to an MRI machine, but the same technology/forces can have countless negative impacts on the human body. It is completely dependent on the frequency of each force and the amount of time exposed to these forces.

  
  

  NEXT QUESTION: In hospitals, most MRI machines have a power of 1.5 to 3 Tesla, what impact would increasing the strength of a magnetic resonance imaging machine have? Could this have even more of an impact on patients? How does the strength of the machine relate to the imaging it provides?

Over time, improvements to major MRI system components like magnetic field gradient coils and radio frequency receiver array coils, have achieved higher signal-to-noise ratio and higher resolution imaging or acceleration. 

A next generation MRI scanner uses ultra-high field scanners, and a head-only magnetic gradient coil, receiver coils, and transmit coils. The gradient coil, a key component, has two layers of conductive wiring. One creates a magnetic field inside the coil for spatial encoding images while the other cancels the external magnetic field to diminish eddy currents in the surrounding superconducting magnet.

MRI works on the millimetre scale. Using quantum sensors, a team of researchers at the University of Waterloo have developed a novel way of generating magnetic fields on the nanometre light scale for imaging and controlling nuclear spins, so that measurements can be done at the molecular level instead of physical. This imaging technique has been called nuclear magnetic resonance diffraction (NMRD) because diffraction effectively analyzes crystalline materials like proteins.

Hyperpolarization is a process which prepares a substance outside the body in a state where its magnetic properties are near a maximum, helping create MRI images. Before this substance is injected into the patient, much quality control is done which can be a tedious process. Researchers are using pumped atomic magnetometers to have real time detection of the fields created by hyperpolarized molecules allowing better imaging and observations. The advancement in hyperpolarization and the potential of atomic sensors is exciting. Atomic sensors could be used for many other applications like monitoring macromolecules in chemical processes while hyperpolarization research could significantly reduce cost and challenges of MRI.

Key Takeaway: Physics research like magnets and atomic sensors are allowing MRI processes, systems, and imaging to become efficient, less time-consuming, and cost effective.

Next Question: How will quantum technology improve MRI processing speeds and imaging?

Roller coasters use seat restraints that prevent the occupants from remaining in motion (flying out of the seat) during the changes in direction and accelerative forces for the duration of the ride (Explained by Newton's first law). The seat restraint will exert an equal and opposite force on the occupant (Newton's third law), which can have direct contact physical consequences to a human body. 

• ‘g’ forces also act on the human body in different directions or axes. This can be incredibly dangerous with the sudden and fast changes you experience during a ride on a roller coaster. These axes are typically called the x, y, and z axes. Each axis has a positive or negative direction. For example, when standing upright, the force of gravity acts along the longitudinal / gz axis, parallel to a human spinal cord. In terms of affecting our bodies functions, gz is the most relevant, as it is the most frequently experienced, and is also said to have more significant physiologic effects. This is the type of ‘g’ you would experience on a roller coaster. 

• Fu facts: gx is most commonly experienced by astronauts during launch, and gy by fighter jet pilots! 

• Effects on the human body: Circulatory system. At 1'g' the blood pressure in an upright person is highest in the lower extremities, such as legs. In the brain, it is at its lowest intracerebrally, which means in the cranium. When the g forces on a roller coaster increase, a larger discrepancy of blood pressures between the cranium and the lower body may occur. If the rider experiences multiple g forces over a prolonged period of time, the effect will be significant cerebral hypoxia, which means no blood flow, and no oxygen flow throughout bodily systems. This phenomenon should only happen if the roller coaster has been inappropriately designed, or the ride already experiences blood pressure related health issues. 

• Effects on the human body: Respiratory system. G forces may interrupt the respiratory system by shifting blood to the lung bases. This will cause the collapse of alveoli (tiny air sacs), and creates general perfusion mismatch and extreme breathing problems for the rider. This can be incredibly dangerous, and contributes to the hypoxia by delivering oxygen-lacking blood. 

• Effects on the human body: Physical. Many riders experience musculoskeletal pain, especially in stacked joint systems, such as the back and the neck. The very effect of the g forces causes extreme pressure build-up to release cycles, which over time or continuous rides may permanently alter the skeletons capacity to handle even just earth's natural gravitational force. In addition, the seat restraint exerting the opposite force directly to your body can cause serious damage; with enough force, the roller coaster must be traveling at high speeds, and the occupant / rider must be an adult (or have a higher mass), but there exists a possibility of organ rupture, broken bones / ribs, or serious pressure related internal injuries. All due to the equal and opposite reaction by the seat restraint. This result is correlated to poorly designed seats, or when an occupant is improperly suited to fit the restraint. 

• NEXT QUESTION: What specific design features in modern roller coasters help mitigate / eliminate the negative physiological impacts of high g-forces on riders? Are there any? If so, how do they work / what’s the science behind them? 

Additionally, to maintain trust in medical diagnoses, accurate images are a need to produce the right treatment plan. Quantum computing enhances image quality by improving signal-to-noise ratios and higher resolution. The algorithms are good at using complex data to make clearer images, and reducing artefacts-unnatural occurrences in imaging that impact efficiency and final diagnoses. In MRI, quantum computing can be used to adjust parameters to adapt to the patient's anatomy and regions of interest. This also improves image quality and time use, which lowers the discomfort for patients and gives a chance to see others.

Another improvement quantum computing will bring is changes to image analysis and interpretation. Its ability to compute data will make it easier to extract information and notice abnormalities that may not be easy to spot with other traditional methods.

Types of quantum computers

Superconducting Qubits

• use superconducting circuits to create qubits

Trapped Ion Qubits

• use ions trapped using electromagnetic fields

Topological Qubits

• use anyons, particles only existing in 2D

Quantum Dots

• -use semiconductor nanocrystals

Photonic Quantum Computers

• use photons for qubits

*qubits=the basic unit of information in quantum computing

Next question: How are gravitational, electromagnetic, and strong and weak nuclear forces involved in quantum technology?

In opposition, "low-field" MRI are better at scanning organs that are surrounded by or filled with air, ex. bowels, lungs, sinuses, etc and technically would be safer due to the lower exposure to the frequencies. As well as be able to capture the heart and lungs and guide minimally invasive procedures with decent accuracy and catheters. "Low-field" MRI are able to be more accessible with their design to accommodate for claustrophobia and obesity.

The effects of "high-field" MRI which in some cases can perform human imaging infields up to 11.7T. Which can cause more serious harm to the human body and the machine but can create higher quality of images.

Next Question: How might the friction play a role in a high-field MRI machine to ensure the quality of the imaging?

If a roller coaster has no forces acting against it, it could technically run forever. This can be attributed to the law of Inertia. Theorized by Sir. Issac Newton in 1687, Inertia states that: an object in motion will remain in motion and an object at rest will remain at rest, unless acted upon by an outside force. This can be seen in roller coasters, as if a coaster was not acted upon by an outside force, it would remain in motion due to the momentum and speed the cart has built and never stop. But a roller coaster does slow down and eventually stop. So what outside forces are causing a roller coaster to lose speed?

FRICTION:

What is friction? - friction is an external force that opposes the motion of an object.

• When a roller coaster is moving with its momentum and acceleration due to gravity, there is always a force of friction acting against it in the opposite direction. This is due to the wheels of the car rubbing against the track, creating heat due to this friction, eventually this friction will gradually slow the coaster.

AIR RESISTANCE:

What is air Resistance? - the force that is in opposition of an object moving through air.

• Air Resistance slows or resists the movement of objects, and in the case of roller coasters it can affect it's motion and speed, but not in a very significant way.

• Air Resistance happens when air particles collide with the surface of the coaster's cart. As the speed of an object increases, so does the amount of air resistance acting up on it. This is due to the frequency in which the air particles are colliding the coaster's cart

IMPACT ON PASSENGERS:

• With friction and Air Resistance acting on a roller coaster during it's ride, the passengers on board will also experience the same forces as they are attached to the object that is experiencing them. The amount of friction a roller coaster cart experiences will also increase due to the passengers, since it's mass will become larger due to the weight of the passengers.

• If roller coasters did not experience forces acting against them, they would be incredibly unsafe to ride as they would go constantly resulting in dangerous amounts of acceleration and G-Forces acting on the human body.

  
  

NEXT QUESTION: How do the forces acting on a roller coaster vary during different points on the coaster? (E.g. Gravity at the top of the first hill). And how are these forces balanced to ensure the roller coaster remains safe for passengers?

• NEXT QUESTION: How do variations in track design, such as the shape and height of hills, loops and turns, influence the balance between gravitational potential energy, kinetic energy, and g-forces on a roller coaster, and how can engineers optimize these variables to maximize rider safety? 

Passengers are also protected by harnesses and seat belts to secure riders throughout the ride and protect them from effects of inertia. There are also a variation of brake systems in rollercoasters, such as:

• Chain lifts: to ensure the carts move in the appropriate direction when climbing a hill.

• Block brakes: Assist in ensuring the ride stops at its ending and the passengers can exit the ride.

• Trim brakes: They are used to slowing down or stop a ride during certain points and may be used to build suspense when climbing a hill on the ride. They can also be used during emergency stops during the ride. 

• Computers: Assist on eliminating the factors of possible human errors. They are most commonly used when there are multiple carts on rides to ensure there is proper distance between the carts. They also control certain mechanical equipment and used during launch phases. 

Next Question: How are the brake systems used to stop or slow down fast moving carts? Do they use more than just friction to stop rides? If so, what other kind of brake systems do roller coasters use?

Gadolinium-based contrast agents (GBCAs) are used in patients to enhance the visibility of the imaging. A study has reported that deposits of the chemical remained in the brain of some patients after repeated use of the agents in MRI. The agents may cause injury to kidneys, nephrogenic systemic fibrosis, and narrowing of the arteries. Children, pregnant women, and people with inflammatory or kidney problems are at a higher risk of developing gadolinium toxicity due to multiple MRIs.

Next Question: What impact do different frequencies produced by MRIs have on the human body?

Blocks and Sensors

-roller coasters are divided into sections that are called blocks and separated by a braking point, they prevent trains being on a single block at the same time

-sensors of the block system keep track of where each train is

-the sensors work off proximity and are typically inductive-when two trains are on the same block, they signal the brakes to stop the back train

-this brake system is used mainly to prevent collision and monitor speeds

Fin Brakes

-hang down over the rails of the track

-a controlled hydraulic system makes the brakes squeeze and close over metal fins under the train

-the force of friction makes the train slow down gradually

-they are inspected daily to make sure they are fixed to the train and aren’t worn

Magnetic Brakes

-usually two rows of magnets that interact with a magnetic field at the back

-eddy forces that are generated by this field push against the direction of the train and slow it down

-however, magnetic brakes can’t stop trains completely

-a fin brake is also attached to actually stop the train

Skid Brakes

-mostly on old roller coasters

-friction slows the train down as it uses large ceramic plates that go upwards and push against the bottom of the track

-they are not common because they do not fit current designs

Next question: How have roller coaster brakes evolved since the basic concepts of them? What factors were considered in the creation of these brakes and why has it changed since then?

• Serbian-American scientist Nikola Tesla pioneered the use of alternating current, which is a large part of the function of an MRI machine. These currents are present when the changing magnetic field is active.

Low-Field MRI Machines:

• Low-Field MRI machines have a power of below 1T. This means that since the field strength is lower, it will generate less signal, reduce the quality of the pictures resolution, and result in longer scan times for patients

• Low-Field MRI machines are much more affordable to install, they are smaller, require much less shielding for patients, and due to it's open design, the access and visibility of patients is improved.

High-Field MRI Machines:

• High-Field MRI machines work with a superconducting magnet, and the higher amount of signal produced improves spatial contrast and image resolution compared to the Low-Field alternative.

• Higher Field MRI machines used to rely a lot on helium for their function, but this has been very reduced/eliminated as the technology has evolved.

• Patients must wear more shielding to protect themselves, the machines are much more expensive to install, and due to a closed design, patient accessibility is reduced and larger patients could struggle to fit.

What is a Superconducting Magnet?

A type of magnet that generates a magnetic field free from electrical resistance. They are made from coils of superconducting wire.

In summary of this:

MRI machines with higher Tesla improve the resolution of images produced during the MRI process and provide very detailed pictures of inside a patients body.

So why don't all hospitals use the highest Tesla MRI machines?

• As the strength of the magnetic field of an MRI machine increases so does the price. One main reason hospitals opt for machines that are 1.5-3T is due to the incredibly high price to install and operate a higher-field MRI machine. (a 7T scanner, which is not even the highest has a minimum cost of $7 million)

• As the strength increases so does the need for cooling and protection for the patients. The machines can produce much more heat and require to be cooled when the field is so high.

• More shielding will be required for patients as the higher fields can have more of an impact on a patients health, making it a slightly more invasive process

• While yes, an ultra-high field machine can produce images with a much better resolution, it is better suited for research purposes instead of clinical use.

NEXT QUESTION: With the use of higher field MRI machines for research purposes, what is being discovered/what can be discovered? Could these machines eventually make their way into clinical use?

According to Newton’s first law of motion, an object in motion stays in motion unless acted upon by an external force. Hence, when the car is moving up a hill, the opposite force is gravity, converting the car’s kinetic energy into potential energy again, making the car lose momentum. When a roller coaster moves downwards and increases velocity, its momentum increases. If there’s more momentum, it’s harder to stop the car so roller coasters have hills, loops, curves, and other ways to make the car lose momentum near the end of the ride. Lastly, As a roller coaster rubs along the rails, it wheels along the rails, and friction is produced as a result of the heat. This friction slows down the roller coaster.

Momentum is equal to an object’s mass multiplied by its velocity.

Next Question: How do other Newton's Laws of Motion apply to roller coasters?