Physics Final Project by https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750 Physics concepts en-us 2021-05-09 22:49:44 UTC 2021-05-24 00:08:32 UTC hello@padlet.com Gravity and Free Fall chloe_michelle_colin https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1507086714
  • Acceleration of Gravity according to free fall: 9.8 m/s2
  • What is gravity and what are some real life examples?
    • Gravity is a force that was discovered by Sir Isaac Newton
    • It is the force that pulls down on objects on earth at a rate of 9.8 m/s2
    • For example when looking at a scale it tells you your weight not your mass because it takes gravity into consideration. If you were to travel to the moon, you would be much lighter because there is less gravity.
    • Using gravity and free fall equations you can calculate how fast a ball will fall and how high you can throw something.
  • What is free fall?
    • Free fall is when an object is falling at a constant rate
    • Free fall neglects air friction so that the object accelerates at 9.8 m/s2
    • Definition according to book: "an idealized situation in which air friction is ignored and objects accelerate at a constant downward 9.8 m/s2"(Pg 120).
  • Important equations
    • v = v0 + gt
    • x = x0 + v0t + ½gt2
    • v = v0 + at
  • Example Problems:
    • Say an object is thrown upwards what would be the acceleration at its highest point? 
      1. Answer: -9.8 m/s2
    • Jed drops a 5.0 kg box off of the Eiffel Tower. After 4.2 seconds, how fast is the box moving? 
      1. Answer: 41 m/s
    •  Jerry measures the time it took for a ball dropped from a balcony to hit the ground. His stopwatch reads 1.8 s. How high is the balcony?
      1. Answer: 16m
    • ]]>     2021-05-09 22:58:32 UTC https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1507086714     Conservation of Energy chloe_michelle_colin https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1507148579
  • What is Potential Energy?
    • Energy that is stored because the object is not yet in motion.  
    • "The energy of position"(Pg 257).
    • Potential energy is stored until it becomes active.
    • What is Kinetic Energy?
      • "Energy due to motion"
      • If velocity is 0, then Kinetic energy is 0. The larger the velocity the larger the kinetic energy.
      • If an object in motion has mass then it has kinetic energy.
    1. Law of Conservation of Energy
      • "Energy cannot be created or destroyed-only transformed from one form into another. The total energy in a closed system remains constant"(Pg 279).
      • "In a closed system the total energy at the start is the same as the total energy at any later time or in any other configuration of the system"(Pg 279).
    2. What is Hooke's law
      • W= FD
      • The amount of work produced is calculated by the amount of inserted force and the distance 
    3. Important Equations
      • E initial = E final
      • Etotal = mgh + ½mv2 + ½kx2
      • Wnet=ΔEk
      • Ek=½mv2
      • Ep= ½kx2
      • Ep= mgh
    4. How does Conservation of Energy applies to real life?
      • When you do things such as turning lights on and off you are using energy. "Using these resources does not destroy the energy; instead, the energy is turned into heat, chemical change, and other forms"(Pg 279). Energy comes in many forms and we use it every day.
      • Another example of converting energy is when you burn petroleum oil. The energy cannot simply disappear so it converts into heat and light(Sciencetopia.net).
    5. Example Problems
      • A ball falls from a height of 8.0 m. How fast is it traveling when it hits the ground?
        1. Answer: 13m/s
      • What is the speed of a 2000 kg car that has a kinetic energy of 500,000 Joules 
        1. Answer: 22.36 m/s
      •  A hockey puck with mass 0.24 kg slides across the ice. A hockey player uses her stick to slow down the puck by applying a 8.2 N force over a distance of 0.30 m. What is the change in the energy of the puck
        1. Answer: 2.46 J 
    ]]>     2021-05-09 23:51:38 UTC https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1507148579     Momentum and Impulse chloe_michelle_colin https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1507377424
  • What is momentum?
    • p=mv
    • Momentum can be calculated by multiplying velocity and the mass of the object.
    • "The higher an object’s mass or velocity, the more momentum it has"(Pg 306 ).
  • What is impulse?
    • J=FT
    • J=Pf-Pi
  • How it applies in real life
    • Think about driving. As you are driving you see a stop sign, therefore you must come to a complete stop. You have two choices: slamming on your brakes or slowing down and then coming to a complete stop. Due to the time variable, both have the same impulse despite the amount of force applied(Example on Pg 308).
    • Impulse is defined as "the product of force and the duration of time the force is applied"(Pg 308). 
    • An object's momentum is changed when impulse is applied.
  • Important Equations
    • p=mv
    • F=P/T
    • J=FT
    • J=Pf-Pi
  • Example Problems
    • Which has more momentum, a 4,000 lb car traveling at 60 mph or a 30,000 kg truck traveling at 1.5 m/s?
      1. Answer: The Car
    • As Jane approaches a stop sign, she applies a braking force of 10,000 N. Her car has a mass of 2,000 kg and is moving with a velocity of +20 m/s. What is the impulse imparted to bring the car to a stop?
      1. Answer: -40,000 kg m/s
    •  A bowling ball has a mass of 3.5 kg and is traveling with a velocity of 21 m/s down the lane. How much momentum does it have?
      1. Answer: 74 kg m/s


    • ]]>     2021-05-10 01:40:54 UTC https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1507377424     Simple Machines chloe_michelle_colin https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1507399524
  • What is a simple machine?
    • Simple machines are mechanical devices that make tasks easier.
  • What is Mechanical Advantage?
    • Mechanical advantage is how much easier the task is because of the machine.
    • Using physics, you can calculate the distance and how much force you need to use to move an object.
  • What are the simple machines?
    • Lever
      1. A simple machine that consists of a bar that pivots at a fixed point called a fulcrum
    • Pulley
      1. A simple machine that consists of a rope that fits into a groove in a wheel
    • Wheel and Axel
      1. Two different sized circular objects that are attached together and turn as one
    • Inclined plane
    • Wedge
    • Screw
  • How can this apply to real life?
    • Simple machines are used in everyday life! From the car that you drive to the inclined plane used when moving boxes.
    • You can use these methods to calculate how strong you have to be to lift a box using an inclined plane, how far you need to pull a rope to lift something, and much more.
  • Important Equations
    • MA= Fo/Fi (mechanical advantage)
    • MAlever= Li/Lo (mechanical advantage of a lever)
    • η= Wo/Wi (efficiency)
    • MAideal= Di/Do
    • MAwa= Rw/Ra
    • MAg=τo/τi
  • Example Problems
    • Janelle has a machine with a mechanical advantage of 2.5. She inputs a force of 20 N. What is her output force?
      1. Answer:  50 N
    • A set of pulleys has a mechanical advantage of 1.5 and an ideal mechanical advantage of 2. If you wish to lift a 30 N weight by 10 m how far do you have to pull and how hard?
      1. Answer: 20 N & 20 m
    • Astrid makes a winch using a long crank arm and an axle. When she turns the crank with a force of 40 N, the axle turns and generates a force of 260 N. What is the mechanical advantage of her winch?
      1. Answer: 6.50
    • Rafi uses a pulley system to lift a 16 N weight by 8.0 m. If he pulls his end of the rope a distance of 4.0 m, then what amount of force would he use
      1.  Answer: 32 N

    • ]]>     2021-05-10 01:50:12 UTC https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1507399524     Position and Displacement chloe_michelle_colin https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1507399919
  • What is displacement?
    • Displacement is the distance between two points (the first being the initial location and the second being the final location).
    • Using physics, you can calculate the distance between the two points.
  • How can this apply to real life?
    • Displacement can help in situations such as driving or walking. You are in one location but you must travel how much to get to the next location?
    • Position and displacement are both the easiest and most practical lessons to use in real life.
  • Important Equations
    • Xf= Xi+d
    • v= d/t
  • Example Problems
    • An aircraft takes off from Austin, TX, flies 140 km west, lands, and then takes off again and flies 330 km east. If you define east as positive and west as negative, what is the plane's final position relative to Austin?
      1. Answer: 190km
    •  A car starts at a position of 7 km and moves to a final position of 5 km. What is the displacement of the car?
      1. Answer: -2 km
    • Ryan moves to the right with a positive velocity of 5 m/s for 1 s, then to the left with a negative velocity of −5 m/s for 1 s. What is Ryan’s displacement after 2 s?
      1. Answer: 0 m
    • Alice starts at (3, 3) m and moves displacements of d1 = (-9,12) m, d2 = (4,11) m, and d3 = (-9,-22) m. What is Alice's total displacement?
      1. Answer: (-14, 1) m
    • ]]>     2021-05-10 01:50:22 UTC https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1507399919     Grade (Gravity and Free Fall) kara_hermogeno https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1551792684 Written Explanation 5/6
    Equations 1/2
    Problems 3/3
    Real World 4/5
    Video 4/4]]>     2021-05-23 20:41:12 UTC https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1551792684     Grade (Momentum and Impulse) kara_hermogeno https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1551797961 Written Explanation 5/6 (explain a little more about what it is not just equations - some of this is covered in real life too which is ok)
    Equations 1/2
    Problems 3/3
    Real World 5/5
    Video 4/4]]>     2021-05-23 20:46:36 UTC https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1551797961     Grade (Conservation of Energy) kara_hermogeno https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1551798090 Written Explanation 5/6 (Hooke's Law is 1/2 kx^2 not W = Fd)
    Equations 1/2
    Problems 3/3  (explained in video)
    Real World 5/5
    Video 4/4]]>     2021-05-23 20:46:45 UTC https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1551798090     Grade (Simple Machines) kara_hermogeno https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1551798179 Written Explanation 5/6
    Equations 1/2
    Problems 3/3  (explained in video)
    Real World 5/5
    Video 4/4]]>     2021-05-23 20:46:51 UTC https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1551798179     Grade (Position and Displacement) kara_hermogeno https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1551798321 Written Explanation 5/6
    Equations 1/2 (no explanation is given)
    Problems 3/3 (explained in video)
    Real World 4/5
    Video 4/4]]>     2021-05-23 20:46:57 UTC https://padlet.com/chloe_michelle_colin/xhejlj6bt240k750/wish/1551798321