Impulse Introduction

Impulse

The change in momentum

Momentum Review

Since impulse is the change in momentum, let's review momentum!

Momentum

Everything has mass. So if that object is moving it has momentum!

Momentum is the mass of the object multiplied by the velocity!

Mass in motion

Example #1: Determine the momentum of a 65 kg football player moving west at 3 m/s.

p (momentum) = ?
m (mass) = 65 kg
v (velocity) = 3 m/s, west

Define variables

Finding Velocity

Finding mass

Multiple Choice

A stationary object has a nonzero momentum

• True

• False

Multiple Choice

A 10 kg object is pushed at a speed of 5 m/s. Calculate the momentum of the object.

• 50 m/s

• 50 kg*m/s

• 125 m/s

• 125 kg*m/s

Multiple Choice

Find the mass of an object that has a momentum of 25 kg*m/s and is moving 5 m/s.

• 5 kg

• 125 kg

• 0.2 kg

• 100 kg

Impulse

Change in momentum

• Airbag in a car: The airbag exerts a force on the person over a longer time than if the driver were to hit the dashboard directly.

• Kicking a soccer ball: The player's foot exerts a force on the ball for a short duration, causing a change in the ball's velocity (momentum).

• Rocket launch: The rocket's engine creates a force that changes the object's velocity (momentum) and propels the rocket upward.

• Slamming the brakes of a car: The braking force applied causes the car to slow down (a change in momentum).

Multiple Choice

What is the definition of impulse?

• The distance an object travels

• The speed of an object

• The change in momentum of an object.

• The force of gravity on an object.

Multiple Choice

Give an example where impulse is involved.

• When a baseball player hits a ball with a bat

• When a person is sleeping in bed

• When a car is parked in a garage

Multiple Choice

Explain the difference between impulse and momentum.

• Impulse and momentum are the same thing

• Impulse is the change in momentum of an object, while momentum is the product of an object's mass and velocity.

• Impulse is the product of an object's mass and its velocity, while momentum is the change in momentum of an object.

• Impulse is the force applied to an object, while momentum is the speed of the object.

Multiple Choice

The air bag on a car reduces the force experienced on the driver by extending the time of impact.

• True

• False

Dropdown

Impulse is ​​the change in ​​

Select answer

​ ​

Multiple Choice

The purpose of air bags on a car is to

• decreasing the time of impact

• increase the force of impact

• increase the time of impact

• decrease the impulse during impact

The product of the average net force on an object and the time interval over which the force acts.

Impulse

I (Impulse) = ?
F (Force) = 5 N
t (time) = 3 seconds

Define Variables

Example: Find the impulse on an object that experiences a 5 N force for 3 seconds.

Multiple Choice

How is impulse calculated?

• Force multiplied by time

• Mass multiplied by acceleration

• Velocity divided by time

• Work divided by distance

Multiple Choice

What happens to the impulse if the force applied on an object is doubled?

• The impulse remains the same.

• The impulse is halved.

• The impulse is doubled.

• The impulse is quadrupled

Multiple Choice

Impulse depends on

• weight and force

• force and time

• electric charge and time

• none of these

Multiple Choice

What happens to the impulse if the time over which a force is applied is halved?

• The impulse remains the same.

• The impulse is quadrupled.

• The impulse is doubled.

• The impulse is halved.

Multiple Choice

What is the impulse experienced when a baseball applies 600 N of force over 0.5 seconds to a catchers mitt?

• 300 Ns

• 1200 Ns

• 3000 Ns

• 600 Ns

Multiple Choice

What is the impulse experienced when 10 N are applied to an object for 0.48 seconds?

• 0 Ns

• 1000 Ns

• 4.8 Ns

• 48 Ns

Multiple Choice

A boy kicks a football with a force of 20 N, the time the force acts for is 0.3 seconds. Calculate the impulse on the ball.

• 1 Ns

• 6 Ns

• 33.3 Ns

• 0.333 Ns

Multiple Choice

If a car bumper experiences a 500 Ns. Impulse over 3.2 seconds, what was the force applied.

• 156.25 N

• -156.25 N

• -500 N

• 500 N

Impulse-Momentum Theorem

​The impulse on an object equals the object's final momentum minus the object's initial momentum.

If the momentum of an object changes from 10 kg*m/s to 50 kg*m/s, what is its change in momentum?
HINT: CHANGE IN MOMENTUM (IMPULSE) IS FINAL MOMENTUM MINUS INITIAL MOMENTUM!

Change in momentum = ?
Final Momentum = 50 kg*m/s
Initial Momentum = 10 kg*m/s

Defining Variables

Multiple Choice

If the momentum of an object changes from 30 kg*m/s to 50 kg*m/s in 2 seconds, what is the impulse?

• 20 kg*m/s

• 10 kg*m/s

• 5 kg*m/s

• 40 kg*m/s

Multiple Choice

If the momentum of an object changes from 40 kg*m/s to 80 kg*m/s in 5 seconds, what is the change in momentum?

• 120 kg*m/s

• 5 kg*m/s

• 320 kg*m/s

• 40 kg*m/s

I (impulse) =?
m (mass) = 2000 kg
v1 (initial velocity) = 15 m/s
v2 (final velocity) = 0 m/s (stopped)

Define Variables

I (impulse) =?
m (mass) = 2000 kg
v1 (initial velocity) = 15 m/s
v2 (final velocity) = 5 m/s

Define Variables

Multiple Choice

What is the change in momentum of a 1500 kg car when it slows down from 35 m/s to 15 m/s

• 30,000 kg*m/s

• 22,500 kg*m/s

• 15,000 kg*m/s

• 52,500 kg*m/s

Multiple Choice

What is the impulse of a 1500 kg car when it slows down from 35 m/s to 15 m/s

• 30,000 Ns

• 22,500 Ns

• 15,000 Ns

• 52,500 Ns

Multiple Choice

If an object with a mass of 12 kg is acted upon by a force that causes its speed to increase from 5 m/s to 10 m/s, find the impulse on the object.

• 1.1 kg*m/s

• 2.4 kg*m/s

• 60 kg*m/s

• 120 kg*m/s

Use this equation:

To find variables like:

• Force

• Time

• Mass

• Final Velocity

• Initial Velocity

Multiple Choice

A 740 kg car traveling at 19 m/s comes to a complete stop in 2.0 s. What is the magnitude of the force exerted on the car during this stop?

• 85 N

• 850 N

• 7030 N

• 9250 N