Momentum and collisions for a test

What is momentum?

Momentum is the product of an object's mass and its velocity: $\displaystyle p = mv$.

What is a collision?

A collision is an event where two or more bodies exert forces on each other for a relatively short time.

True or false: Momentum is a scalar quantity.

False, because momentum is a vector quantity, having both magnitude and direction.

Difference between elastic and inelastic collisions.

In elastic collisions, kinetic energy is conserved. In inelastic collisions, kinetic energy is not conserved.

What is the law of conservation of momentum?

The total momentum before a collision equals the total momentum after the collision in an isolated system.

Fill in the blank: \displaystyle p = _____

$\displaystyle p = mv$, where $\displaystyle m$ is mass and $\displaystyle v$ is velocity.

What happens in a perfectly elastic collision?

Both momentum and kinetic energy are conserved during a perfectly elastic collision.

If two objects collide and stick together, this is called:

An inelastic collision.

What is impulse?

Impulse is the change in momentum of an object when a force is applied over time: $\displaystyle J = F imes t$.

True or false: Impulse is equal to the force applied multiplied by time.

True, because impulse is calculated using $\displaystyle J = F imes t$.

Example of momentum in a real-world scenario.

A moving car has momentum due to its mass and speed, impacting its stopping distance.

What is the formula for kinetic energy?

Kinetic energy is given by $\displaystyle KE = \\frac{1}{2} mv^2$.

Difference between elastic and perfectly inelastic collisions.

In elastic collisions, both momentum and kinetic energy are conserved. In perfectly inelastic collisions, only momentum is conserved.

What is a perfectly elastic collision?

A collision where both momentum and kinetic energy are conserved, no energy lost to sound or heat.

True or false: Momentum can change without a net external force.

False, because a net external force is needed to change momentum.

When two cars collide in an accident, this is an example of:

An inelastic collision, as they crumple and stick together.

What is the effect of mass on momentum?

An increase in mass leads to an increase in momentum if velocity remains constant.

Define impulse-momentum theorem.

Impulse is equal to the change in momentum of an object: $\displaystyle J = \Delta p$.

What is conserved in all collisions?

Momentum is conserved in all types of collisions, provided no external forces act.