Momentum and Impulse

A car's momentum changes from 1200 kg·m/s to 0 in 4 seconds. What is the average force?

• 300 N

• 600 N

• 1200 N

• 4800 N

Answer explanation

The change in momentum is 1200 kg·m/s to 0, so the change is -1200 kg·m/s. Using the formula F = Δp/Δt, we have F = -1200 kg·m/s / 4 s = -300 N. The average force is 300 N in the opposite direction.

Tags

NGSS.HS-PS2-1

What happens to force when the time of momentum change increases?

• Force increases.

• Force decreases.

• Force remains the same.

• Force doubles.

Answer explanation

According to the impulse-momentum theorem, force is equal to the change in momentum divided by the time over which the change occurs. If the time of momentum change increases, the force decreases.

What principle should be used to design a new vehicle safety feature?

• Reduce vehicle mass.

• Increase passenger speed.

• Extend the time of momentum change.

• Decrease the time of momentum change.

Answer explanation

To enhance vehicle safety, extending the time of momentum change is crucial. This principle reduces the force experienced by passengers during a collision, minimizing injury risk, unlike decreasing the time which increases force.

Tags

NGSS.HS-PS2-2

NGSS.HS-PS2-3

What is the unit of momentum in the International System of Units (SI)?

• Newton (N)

• Kilogram meter per second (kg·m/s)

• Joule (J)

• Newton-second (N·s)

Tags

NGSS.HS-PS2-2

The Impulse-Momentum Theorem states that the change in momentum of an object is equal to the:

• force applied divided by the time it is applied.

• velocity of the object.

• impulse applied to it.

• mass of the object.

Tags

NGSS.HS-PS2-2

A 5 kg object moving at 10 m/s has a momentum of:

• 15 kg·m/s

• 50 kg·m/s

• 5 kg·m/s

• 10 kg·m/s

Tags

NGSS.HS-PS2-2

If a force of 20 N is applied for 3 seconds, what is the impulse imparted to the object?

• 60 N·s

• 23 N·s

• 20 N·s

• 6 N·s

The momentum of an object is calculated by multiplying its mass by its:

• acceleration.

• velocity.

• force.

• energy.

Tags

NGSS.HS-PS2-2

An object experiences an impulse of 100 N·s. If the force applied is 50 N, how long was the force applied?

• 0.5 s

• 2 s

• 5 s

• 10 s

Tags

NGSS.HS-PS2-1

Which of the following scenarios involves the highest momentum?

• A 2 kg book moving at 1 m/s.

• A 1 kg ball moving at 3 m/s.

• A 4 kg cat sleeping.

• A 0.5 kg bird flying at 10 m/s.

Tags

NGSS.HS-PS2-2