Lesson 38 Practice Quiz

What is the formula for calculating impulse in a collision?

Which of the following best describes the principle of momentum conservation?

• Momentum is always lost in a collision.

• Momentum is conserved only in elastic collisions.

• The total momentum of a closed system remains constant if no external forces act on it.

• Momentum is conserved only in inelastic collisions.

What is the primary principle behind rocket propulsion?

• Conservation of energy

• Newton's first law of motion

• Conservation of momentum

• Gravitational force

Calculate the impulse experienced by an object if a force of 10 N is applied for 5 seconds.

• 50 Ns

• 15 Ns

• 5 Ns

• 25 Ns

A 2 kg object moving at 3 m/s collides with a stationary 1 kg object. If the collision is perfectly elastic, what is the velocity of the 2 kg object after the collision?

• 1 m/s

• 2 m/s

• 3 m/s

• 0 m/s

Explain how the impulse-momentum theorem is applied in car safety features like airbags.

• Airbags increase the time over which the force acts, reducing the force experienced by passengers.

• Airbags decrease the time over which the force acts, increasing the force experienced by passengers.

• Airbags do not affect the impulse experienced by passengers.

• Airbags increase the momentum of the passengers.

A rocket expels gas at a velocity of 2000 m/s. If the mass of the expelled gas is 5 kg, what is the change in momentum of the rocket?

• 10000 kg·m/s

• 4000 kg·m/s

• 2000 kg·m/s

• 5000 kg·m/s

Which of the following is an application of momentum in sports?

• Using a heavier bat to hit a baseball further

• Wearing lighter shoes for running

• Using a smaller ball in basketball

• Wearing a helmet for safety

Describe how momentum conservation is used in analyzing rocket propulsion.

• The momentum of the rocket is conserved by increasing its mass.

• The momentum of the expelled gas is equal and opposite to the momentum gained by the rocket.

• The momentum of the rocket is conserved by decreasing its velocity.

• The momentum of the rocket is not affected by the expelled gas.

If a force of 20 N is applied to an object for 3 seconds, what is the change in momentum of the object?

• 60 kg·m/s

• 40 kg·m/s

• 20 kg·m/s

• 80 kg·m/s