5.1.1 Linear Momentum and Impulse

Question 1

Linear Momentum and Impulse

Answer 1

• Momentum is defined as the product of mass and velocity: .
• The general form of Newton’s second law is .
• Impulse is the change in momentum or the integral of force over an interval of time:

Question 2

A 10 g ball is thrown with a speed of 2 m / s at a wall. It bounces off the wall with a speed of 2 m / s. Assume that the ball was in contact with the wall for 0.01 s. How much force did the ball exert on the wall?

Answer 2

4 N

Question 3

To determine the amount of impulse imparted to a 1 g golf ball after it is hit for 0.01 s by a 1 kg golf club, you must know __________________.

Answer 3

the velocity of the golf ball after impact

Question 4

Why does an egg not necessarily break if you catch it with your hand, while it does break if you drop it into a bowl?

Answer 4

The contact time and surface between your hand and the egg is greater than that between the egg and the bowl.

Question 5

A twelve-gauge shotgun fires a round of ammunition with a mass of 2 g and a velocity of 200 m / s. If it takes 0.01 s for the round to leave the gun, how much force will the shooter feel?

Answer 5

40 N

Question 6

A small rocket that is lifting off vertically loses 100 kg of fuel per second and is moving at a constant velocity of 50 m / s. How much force is the engine exerting?

Answer 6

5,000 N

Question 7

A hammer head with a mass of 2 kg strikes a nail with a force of 50 N. If the contact lasts for 0.1 s, how fast was the hammer going at the moment of impact?

Answer 7

2.5 m / s

Question 8

Which of the following is the momentum of a 10 g ball moving at 2 m / s?

Answer 8

0.02 kg m / s