AP Physics 1 impulse and force-time graphs practice questions

Impulse definition?

Impulse is the change in momentum of an object when a force is applied over time. It is calculated as: Impulse = Force × Time.

Calculate impulse from a force-time graph.

Impulse is represented by the area under the force-time graph. For a rectangular area: Impulse = Force × Duration.

True or False: Impulse can change an object's velocity.

True. Impulse changes momentum; thus, it can change the object's velocity.

Momentum formula?

Momentum (p) is defined as: $\displaystyle p = mv$, where m is mass and v is velocity.

Relationship between impulse and momentum?

Impulse equals the change in momentum: Impulse = Δp = p_{final} - p_{initial}.

Fill in the blank: Impulse is measured in _____.

Impulse is measured in Newton-seconds (Ns) or kg·m/s.

Example: A 2 kg ball accelerates from 0 to 4 m/s.

Initial momentum = 0 kg·m/s. Final momentum = 2 kg × 4 m/s = 8 kg·m/s. Impulse = 8 kg·m/s.

What affects impulse?

Impulse is affected by the magnitude of the force and the duration of time over which the force acts.

Impulse in a crash scenario?

Impulse is crucial in crash scenarios: greater impulse leads to higher momentum change, impacting safety.

Compare elastic and inelastic collisions.

Elastic: total momentum and kinetic energy conserved. Inelastic: total momentum conserved, kinetic energy not conserved.

What happens during a longer force application?

A longer force application increases impulse, resulting in a greater change in momentum.

Is impulse a vector or scalar?

Impulse is a vector quantity; it has both magnitude and direction.

Calculate momentum change: 5 kg object, from 3 m/s to 7 m/s.

Initial momentum = 5 kg × 3 m/s = 15 kg·m/s. Final momentum = 5 kg × 7 m/s = 35 kg·m/s. Change = 20 kg·m/s.

True or False: Impulse can be negative.

True. Impulse can be negative if the force acts in the opposite direction of the motion.

Formula for change in momentum?

Change in momentum is calculated as: Δp = m(v_{final} - v_{initial}).

Impulse during a foul shot in basketball?

The player's force on the ball over time creates impulse, influencing its velocity and direction.

What does the area under a force-time graph represent?

Impulse. It quantifies the change in momentum of an object.

True or False: A flat force-time graph indicates constant force.

True. A flat line shows force remains the same over time.

Fill in the blank: Impulse is equal to ______.

the change in momentum.

How to calculate impulse from a force-time graph?

Calculate the area under the curve. Units: Newton-seconds (Ns).

What does a triangular area in a force-time graph signify?

The impulse is calculated as: Area = 0.5 × base × height.

Cause → Effect: A larger force applied over a longer time results in?

A greater impulse and change in momentum.

Compare: Impulse vs. Work.

Impulse relates to momentum change. Work relates to energy transfer.

True or False: A force-time graph can show negative forces.

True. Negative force indicates direction opposite to positive reference.

If a force-time graph has multiple peaks, what does it indicate?

Variable forces applied over time, affecting impulse differently with each peak.

What is the significance of the slope in a force-time graph?

The slope represents the rate of change of force with respect to time.

Calculate the impulse: Force of 10 N for 4 s.

Impulse = Force × Time = 10 N × 4 s = 40 Ns.

What does a zero area under the force-time graph mean?

No net impulse, indicating no change in momentum.