# data[].attributes.body
Rmember the laws of motion.

# data[].attributes.body
The first law of motion is that

If an object is at rest it will stay at rest unless

an force moves it same the other way.

# data[].attributes.attachment_link.readable_text
Newton, Motion and Force

It is easy to recognize an object in motion and an object at rest. Super-sonic jets, race cars and even my mini-van can be objects in motion or at rest. What keeps an object at rest or in motion? What causes an object at rest to move? Furthermore, what causes an object in motion to stop? Well, the short answer to these questions is force, which is any influence that causes an object to change its shape or motion.

For example, I must apply force to move a heavy object, such as my chair or a set of dumbbells. In fact, I have to apply a force, albeit not as much, to move even a lighter object, such as my pencil. If I press down on a ball of clay, the force of my hand causes the clay to change its shape. In this lesson, we will explore the relationship between force and motion as explained by Newton's laws.

What is Newton's First Law of Motion?

Newton's first law of motion states that an object at rest remains at rest and an object in motion remains in motion with the same velocity unless acted upon by what we call an unbalanced force. Let's break this law down by defining some key terms. Velocity is the speed of an object in a specified direction. An is an external force that changes the motion of an object. When an object is at rest or moving at a constant velocity, all the forces acting on it are balanced.

For example, my cup of coffee is resting on my kitchen table as I make this lesson. The force of gravity pulling down is balanced by the force of my kitchen table pushing up on my cup of coffee. Now, if I am to move my coffee, I must apply an external force to disrupt the balance. Thank goodness my muscles are strong enough to apply such a force so I can enjoy my cup of coffee. Ah, now that's good joe! Newton's first law of motion is also referred to as the . Inertia is simply the resistance to change in motion. In short, objects tend to keep doing what they are already doing.

Application of Newton's First Law of Motion

There are plenty of applications to Newton's first law of motion. Consider a car moving west along a highway with a constant velocity of 65 miles per hour. What happens when the driver takes his foot off the gas pedal? According to Newton's first law of motion, the car should remain at a velocity of 65 mph, as long as the forces are balanced. As we have witnessed, however, the car slows down, and it comes to rest. This observation begs the question: what external forces act on the car to stop its motion?

The answer is friction. Friction is a force acting in the opposite direction of motion when two objects come into contact with each other. Without external forces, the car would continue to move west at 65 mph. Now, consider a golfer hitting a ball off the tee. While the ball is on the tee, it is said to be at rest. That is, it has no motion. Once the swinging club comes into contact with the ball, the club applies an external force, disrupts the state of balance and sends the ball flying into motion.

How Does Newton's Law Apply to Liquids?

Now, I like coffee, so let's see how Newton's law of motion applies to drinking coffee and driving. While the car is at rest, or even moving at a constant velocity, so is the coffee, and it stays in the cup. But, what happens to the coffee if you increase velocity in a forward direction? The coffee keeps doing what it has been doing and ends up in your lap; that is, assuming there is no lid on the cup. Let's break it down.

When you push on the gas pedal, the wheels spin. However, the road applies a force to the wheels and pushes the car forward. The back of the seat applies a force to your back and pushes you forward as well. But, what about the coffee? The coffee maintains its velocity at 65 mph, and your lap actually moves forward into the coffee. Ouch!

Just the opposite happens when we hit the car's breaks. The brakes slow or even stop the spinning of the wheels. When braking from a constant velocity of 65 mph, the coffee tends to maintain its velocity of 65 mph, and now it's going to end up on the dash of your car. The coffee experiences inertia when we brake to a stop. The coffee resists the change in motion and keeps moving forward.

# data[].attributes.attachment_link.keywords[]
newton's first law of motion: examples of the effect of force on motion - video & lesson transcript | study.com

# data[].attributes.attachment_link.title
Newton's First Law of Motion: Examples of the Effect of Force on Motion - Video & Lesson Transcript | Study.com

# data[].attributes.attachment_link.description
It is easy to recognize an object in motion and an object at rest. Super-sonic jets, race cars and even my mini-van can be objects in motion or at rest. What keeps an object at rest or in motion? What causes an object at rest to move?

# data[].attributes.body
What is a example of Newton 2nd law?

# data[].attributes.attachment_link.readable_text
Newton's Third Law of Motion

Are you sitting down for this? If not, take a seat. You might notice that you're not falling through the chair or floor. That's because the forces acting on you are balanced. A force is a push or a pull in a given direction. The force of gravity pulling you down against your chair is balanced by the force of the chair pushing up against you.

The forces acting on you as you sit in your chair are just one example of Newton's third law, which states that for every action force there is an equal and opposite reaction force. In fact, all forces come in pairs. No force exists in isolation. That's one of the fundamental symmetries of our universe.

Identifying Action & Reaction Forces

Suppose you're standing on the ground. The force of gravity pulls you down towards the earth, which presses your feet against the ground. Let's call that the action force - the force of your feet against the earth. The reaction force is the force of the earth pushing against your feet.

Now imagine that instead of standing, you decide to jump.

Action: You push your feet down against the ground.
Reaction: The ground pushes back up against your feet.

When you take a step forward, your feet are pushing back against the ground; it is only because the ground pushes back against your feet in the forward direction that you're able to move forward.

Now, on to some trickier examples of Newton's third law:

How does a rocket move in space where there's nothing to push off of?

A rocket is basically a controlled explosion. As the rocket fuel burns, it quickly expands outwards in every direction, including against the rocket itself. Here's where Newton's third law comes in.

Action: The expanding gas particles push against the rocket.
Reaction: The rocket pushes against the expanding gas particles.

Equal and Opposite

All of the examples we've discussed so far have involved direct contact between two objects, so let's expand our horizons a bit.

You probably know that the moon orbits the Earth because it feels the tug of Earth's gravity. Let's call the action force the force of the Earth's gravity pulling on the moon. Where's the reaction force? Well, since the moon has mass, it also has its own gravitational field. The moon actually pulls on the Earth with the same force that the Earth pulls on the moon.

# data[].attributes.attachment_link.keywords[]
newton's third law of motion: examples of the relationship between two forces - video & lesson transcript | study.com

# data[].attributes.attachment_link.title
Newton's Third Law of Motion: Examples of the Relationship Between Two Forces - Video & Lesson Transcript | Study.com

# data[].attributes.attachment_link.description
Are you sitting down for this? If not, take a seat. You might notice that you're not falling through the chair or floor. That's because the forces acting on you are balanced. A force is a push or a pull in a given direction.

# data[].attributes.attachment_link.readable_text
Newton's Second Law of

Consider two balls, one with a mass of 1 kg and the other with a mass of 10 kg. Which ball would experience a greater change in motion if kicked with the same force? Clearly, the smaller ball would experience a greater change in motion. An object's state of motion can be described as its velocity, where velocity is the speed of an object with respect to its direction. Objects at rest - for example, the balls you see on the screen - have zero velocity. Once kicked, the ball's state of motion changes. In other words, its velocity changes. When an object changes its velocity, it has what we call acceleration. Newton's second law of motion provides the explanation for the behavior of objects when forces are applied. The law states that external forces cause objects to accelerate, and the amount of acceleration is directly proportional to the net force acting on the objects and inversely proportional to the mass of the objects.

What is Net Force?

Notice that Newton's second law states that the amount of acceleration is directly proportional to the net force acting on the object. What is the net force and how do we calculate it? Net force is the sum of all forces acting on an object in a particular direction. Since forces have direction, they are vector quantities. Vector quantities are fully described with both magnitude and direction and are represented with arrows. Consider an object being pushed to the left with 10 of force and to the right with 5 Newtons of force. The net force = 5 N to the left as 10 N - 5 N = 5 N. The forces are subtracted from each other since they are pointing in opposite directions. The forces would be added to each other if they were pointing in the same direction. Once the net force is determined, the acceleration of the object can be determined.

How to Calculate for Acceleration

Acceleration is a change in velocity. As long as we know the mass of the object and the net force acting on the object, we can determine acceleration. Let's look at the formula:

a = f (net) / m, where a = acceleration, f (net) = the net force acting on the object, m = the mass of the object.

Acceleration Example

Let's look at an example. Consider a 10 kg object forced to the left with 10 Newtons and to the right with 20 Newtosn. What is the acceleration of this object?

Let's recall the formula for acceleration. a = f (net) / m

Let's first calculate the net force. As the forces are acting in opposite directions, we subtract them.

f (net) = 20 N right - 10 N left, and we get f (net) = 10 N right

Now, plug net force into the equation with mass to calculate for acceleration.

A Newton of force equals 1 kg * m/sec^2. 1 N = 1 kg * m/sec^2. If we substitute this value of a Newton into the equation, mass (kg) is cancelled out, and that leaves us with the units m/sec^2. Those are the units for acceleration.

Therefore the acceleration of our object is, a = 1 m/sec^2.

How to Calculate for Force

If we know the mass and acceleration of an object, we can calculate for force. Simply rearrange the equation to solve for force. So, as you see on the screen, f (net) = m * a.

Force Example

Consider again our 10 kg object, now moving to the west with an acceleration of 10 m/sec^2. What is the net force acting on this object?

# data[].attributes.attachment_link.keywords[]
newton's second law of motion: the relationship between force and acceleration - video & lesson transcript | study.com

# data[].attributes.attachment_link.title
Newton's Second Law of Motion: The Relationship Between Force and Acceleration - Video & Lesson Transcript | Study.com

# data[].attributes.attachment_link.description
Consider two balls, one with a mass of 1 kg and the other with a mass of 10 kg. Which ball would experience a greater change in motion if kicked with the same force? Clearly, the smaller ball would experience a greater change in motion.

# data[].attributes.body
The third law of motion is that every action has a equal and opposite reaction.

# data[].attributes.body
The second law of motion is that

the acceleration of an object is dependent

upon two variables - the net force acting upon the object

and the mass of the object.

# data[].attributes.body
A video of all the laws of motion

# data[].attributes.body
The first law of motion is that

If an object is at rest it will stay at rest unless

an force moves it same the other way.

# data[].attributes.attachment_link.readable_text
Newton, Motion and Force

It is easy to recognize an object in motion and an object at rest. Super-sonic jets, race cars and even my mini-van can be objects in motion or at rest. What keeps an object at rest or in motion? What causes an object at rest to move? Furthermore, what causes an object in motion to stop? Well, the short answer to these questions is force, which is any influence that causes an object to change its shape or motion.

For example, I must apply force to move a heavy object, such as my chair or a set of dumbbells. In fact, I have to apply a force, albeit not as much, to move even a lighter object, such as my pencil. If I press down on a ball of clay, the force of my hand causes the clay to change its shape. In this lesson, we will explore the relationship between force and motion as explained by Newton's laws.

What is Newton's First Law of Motion?

Newton's first law of motion states that an object at rest remains at rest and an object in motion remains in motion with the same velocity unless acted upon by what we call an unbalanced force. Let's break this law down by defining some key terms. Velocity is the speed of an object in a specified direction. An is an external force that changes the motion of an object. When an object is at rest or moving at a constant velocity, all the forces acting on it are balanced.

For example, my cup of coffee is resting on my kitchen table as I make this lesson. The force of gravity pulling down is balanced by the force of my kitchen table pushing up on my cup of coffee. Now, if I am to move my coffee, I must apply an external force to disrupt the balance. Thank goodness my muscles are strong enough to apply such a force so I can enjoy my cup of coffee. Ah, now that's good joe! Newton's first law of motion is also referred to as the . Inertia is simply the resistance to change in motion. In short, objects tend to keep doing what they are already doing.

Application of Newton's First Law of Motion

There are plenty of applications to Newton's first law of motion. Consider a car moving west along a highway with a constant velocity of 65 miles per hour. What happens when the driver takes his foot off the gas pedal? According to Newton's first law of motion, the car should remain at a velocity of 65 mph, as long as the forces are balanced. As we have witnessed, however, the car slows down, and it comes to rest. This observation begs the question: what external forces act on the car to stop its motion?

The answer is friction. Friction is a force acting in the opposite direction of motion when two objects come into contact with each other. Without external forces, the car would continue to move west at 65 mph. Now, consider a golfer hitting a ball off the tee. While the ball is on the tee, it is said to be at rest. That is, it has no motion. Once the swinging club comes into contact with the ball, the club applies an external force, disrupts the state of balance and sends the ball flying into motion.

How Does Newton's Law Apply to Liquids?

Now, I like coffee, so let's see how Newton's law of motion applies to drinking coffee and driving. While the car is at rest, or even moving at a constant velocity, so is the coffee, and it stays in the cup. But, what happens to the coffee if you increase velocity in a forward direction? The coffee keeps doing what it has been doing and ends up in your lap; that is, assuming there is no lid on the cup. Let's break it down.

When you push on the gas pedal, the wheels spin. However, the road applies a force to the wheels and pushes the car forward. The back of the seat applies a force to your back and pushes you forward as well. But, what about the coffee? The coffee maintains its velocity at 65 mph, and your lap actually moves forward into the coffee. Ouch!

Just the opposite happens when we hit the car's breaks. The brakes slow or even stop the spinning of the wheels. When braking from a constant velocity of 65 mph, the coffee tends to maintain its velocity of 65 mph, and now it's going to end up on the dash of your car. The coffee experiences inertia when we brake to a stop. The coffee resists the change in motion and keeps moving forward.

# data[].attributes.attachment_link.keywords[]
newton's first law of motion: examples of the effect of force on motion - video & lesson transcript | study.com

# data[].attributes.attachment_link.title
Newton's First Law of Motion: Examples of the Effect of Force on Motion - Video & Lesson Transcript | Study.com

# data[].attributes.attachment_link.description
It is easy to recognize an object in motion and an object at rest. Super-sonic jets, race cars and even my mini-van can be objects in motion or at rest. What keeps an object at rest or in motion? What causes an object at rest to move?