Physics Work, Power & Energy Review - Concepts

Front

Momentum is defined as the product of an object's mass and its velocity.

Back

The product of an object's mass and velocity

Answer explanation

Momentum is defined as the product of an object's mass and its velocity, making 'The product of an object's mass and velocity' the correct choice. The other options incorrectly describe momentum.

Front

What is the equation for momentum?

Back

Momentum = mass x velocity

Answer explanation

The correct equation for momentum is Momentum = mass x velocity. This formula shows that momentum is directly proportional to both the mass of an object and its velocity, making it the only accurate choice among the options.

Front

Impulse is defined as the change in ____.

Back

momentum

Answer explanation

Impulse is defined as the change in momentum, which is the product of mass and velocity. Therefore, the correct answer is momentum, as impulse directly relates to how momentum changes due to applied forces.

Front

What is needed to change an object's momentum?

Back

A force

Answer explanation

To change an object's momentum, a force must be applied. Momentum is the product of mass and velocity, and a force causes a change in either or both, thus altering momentum.

Front

If an object experiences an impulse and stops, what is its final momentum?

Back

Zero

Answer explanation

When an object experiences an impulse and stops, its final momentum is zero. This is because momentum is conserved, and if the object comes to a complete stop, it has no momentum left.

Front

What does the law of conservation of momentum state?

Back

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

Answer explanation

The correct choice accurately reflects the law of conservation of momentum, which states that in a closed system with no external forces, the total momentum remains constant.

Front

Which of Newton’s laws explains how momentum is conserved in all interactions between objects?

Back

Newton's Third Law

Answer explanation

Newton's Third Law states that for every action, there is an equal and opposite reaction. This principle explains how momentum is conserved in interactions, as the forces between objects are equal and opposite, maintaining total momentum.

Front

What quantities are conserved in elastic collisions?

Back

Momentum and kinetic energy

Answer explanation

In elastic collisions, both momentum and kinetic energy are conserved. This means that the total momentum and total kinetic energy before and after the collision remain constant, making the correct answer 'Momentum and kinetic energy'.

Front

What quantities are conserved in inelastic collisions?

Back

Momentum only

Answer explanation

In inelastic collisions, momentum is conserved while kinetic energy is not. This means that the total momentum before and after the collision remains the same, but some energy is transformed into other forms, like heat or sound.

Front

Work (Physics)

Back

The product of force and displacement in the direction of the force

Answer explanation

Work is defined as the product of force and displacement in the direction of the force. This means that only the component of force that acts in the direction of movement contributes to the work done.