Momentum Flashcard

Front

What is the formula for the momentum (p) of a toy car with mass m and velocity v?

Back

p = mv

Answer explanation

The formula for momentum (p) is given by p=mv, where m is mass and v is velocity. This shows that momentum is the product of an object's mass and its velocity, making this the correct choice.

Front

Units to measure the momentum of a toy car?

Back

kg·m/s

Answer explanation

Momentum is calculated as the product of mass and velocity. Therefore, its units are derived from mass (kg) multiplied by velocity (m/s), resulting in kg·m/s. Thus, the correct unit for measuring momentum is kg·m/s.

Front

During a game of pool, why is momentum conserved when the cue ball collides with another ball on the table?

Back

Because no external forces act on the system.

Answer explanation

Momentum is conserved in a closed system because no external forces act on it. This means that the total momentum before and after the collision remains constant, regardless of the interactions between the objects involved.

Front

During a game of pool, Mia notices that when two balls collide perfectly, what is conserved in this elastic collision?

Back

Both total momentum and total kinetic energy.

Answer explanation

In an elastic collision, both total momentum and total kinetic energy are conserved. This means that the total momentum before the collision equals the total momentum after, and the same applies to kinetic energy.

Front

What happens to the velocity of a rubber ball when it collides elastically with a stationary bowling ball?

Back

It rebounds with a velocity equal to its initial velocity.

Answer explanation

In an elastic collision, the lighter object rebounds with the same speed it had before the collision, but in the opposite direction. Thus, it rebounds with a velocity equal to the initial velocity.

Front

Samuel's car collides elastically with Ava's stationary car. What happens to Ava's car?

Back

Ava's car moves with the initial velocity of Samuel's car.

Answer explanation

In an elastic collision, momentum and kinetic energy are conserved. When one object is stationary, it will move with the initial velocity of the moving object after the collision, making this the correct choice.

Front

During a bumper car ride at the amusement park, Grace and Emma's cars collide and:

Back

Stick together and move as one combined mass.

Answer explanation

In a totally inelastic collision, the objects stick together and move as one combined mass, resulting in a loss of kinetic energy. This distinguishes it from elastic collisions where kinetic energy is conserved.

Front

During a car accident, what happens to the kinetic energy of the vehicles in an inelastic collision?

Back

It is partially converted into heat, sound, and deformation energy.

Answer explanation

In an inelastic collision, kinetic energy is not conserved; some of it is transformed into other forms of energy such as heat, sound, and deformation. Thus, the correct statement is that it is partially converted into these energies.

Front

The final velocity of combined toy cars after a collision is determined by:

Back

The initial momentum and the total mass of the system.

Answer explanation

In an inelastic collision, the final velocity is determined by conserving momentum. The total initial momentum equals the final momentum, which depends on the initial momentum and the total mass of the system.

Front

During a game of bumper cars, what happens regardless of whether the collision is elastic or inelastic?

Back

Total momentum is conserved.

Answer explanation

In both elastic and inelastic collisions, total momentum is conserved due to the law of conservation of momentum. However, total kinetic energy is only conserved in elastic collisions, not inelastic ones.