physics post tes

Which of the following statements about the conservation of momentum is not correct?

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  The total momentum of a system of interacting objects remains constant regardless of forces between the objects.

   

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  Momentum is not conserved for a system of objects in a head-on collision.

   

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  Momentum is conserved for a system of objects pushing away from each other.

   

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  Momentum is conserved when two or more interacting objects push away from each other.

   

After colliding, objects are deformed and lose some kinetic energy. Identify the type of collision.

• inelastic

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  elastic

   

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  nearly elastic

   

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  perfectly inelastic

   

A ball with a momentum of 4.0 kg·m/s hits a wall and bounces straight back without losing any kinetic energy. What is the change in the ball’s momentum?

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  –4.0 kg·m/s

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  –8.0 kg·m/s

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  8.0 kg·m/s

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  0.0 kg·m/s

Two objects move separately after colliding, and both the total momentum and total kinetic energy remain constant. Identify the type of collision.

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  elastic

   

• inelastic

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  nearly elastic

   

•   

  perfectly inelastic

   

The change in an object’s momentum is equal to

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  the product of the force applied to the object and the time interval.

   

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  the product of the mass of the object and the time interval.

   

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  the net external force divided by the time interval.

   

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  the time interval divided by the net external force.

   

Which of the following situations is an example of a significant change in momentum?

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  A bicyclist rides over a leaf on the pavement.

   

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  A helium-filled balloon rises upward into the sky.

   

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  A tennis ball is hit into a net.

   

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  An airplane flies into some scattered white clouds.

   

A billiard ball collides with a second identical ball in an elastic head-on collision. What is the kinetic energy of the system after the collision compared with the kinetic energy before the collision?

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  one-fourth as great

   

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  two times as great

   

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  unchanged

   

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  four times as great

   

A billiard ball collides with a stationary identical billiard ball in an elastic head-on collision. After the collision, which of the following is true of the first ball?

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  It has one-half its initial velocity.

   

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  It moves in the opposite direction.

   

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  It comes to rest.

   

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  It maintains its initial velocity.

   

The law of conservation of momentum states that

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  the total momentum of all objects interacting with one another remains constant regardless of the nature of the forces between the objects.

   

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  the total initial momentum of all objects interacting with one another usually equals the total final momentum.

   

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  the total momentum of all objects interacting with one another is zero.

   

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  the total initial momentum of all objects interacting with one another does not equal the total final momentum.

   

A person sitting in a chair with wheels stands up, causing the chair to roll backward across the floor. The momentum of the chair

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  was zero when the person got out of the chair and increased while the person sat.

   

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  remained the same.

   

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  was greatest while the person sat in the chair.

   

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  was zero while stationary and increased when the person stood.