Physics - Review III (Units 1 - 4)

In the diagram below, a 60.-kilogram roller-skater exerts a 10.-newton force on a 30.-kilogram roller-skater for 0.20 second. What is the magnitude of the impulse applied to the 30.-kilogram roller-skater?

• 50. N•s

• 2.0 N•s

• 6.0 N•s

• 12 N•s

In the diagram below, a 10.-kilogram block is at rest on a plane inclined at 15° to the horizontal. As the angle of the incline is increased to 30.°, the mass of the block will

• decrease

• increase

• remain the same

Two carts are pushed apart by an expanding spring, as shown in the diagram below. If the average force on the 1-kilogram cart is 1 newton, what is the average force on the 2-kilogram cart?

• 1 N

• 0.0 N

• 0.5 N

• 4 N

The diagram below shows a sled and rider sliding down a snow-covered hill that makes an angle of 30.° with the horizontal. Which vector best represents the direction of the normal force, FN, exerted by the hill on the sled?

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The diagram below represents a block at rest on an incline. Which diagram best represents the forces acting on the block? (F_f = frictional force, F_N = normal force, and F_w = weight.)

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In the diagram below, a block of mass M initially at rest on a frictionless horizontal surface is struck by a bullet of mass m moving with horizontal velocity v. What is the velocity of the bullet-block system after the bullet embeds itself in the block?

• $\left(\frac{M+v}{M}\right)m$

• $\left(\frac{m+M}{m}\right)v$

• $\left(\frac{m+v}{M}\right)m$

• $\left(\frac{m}{m+M}\right)v$

A 60-kilogram student jumps down from a laboratory counter. At the instant he lands on the floor his speed is 3 meters per second. If the student stops in 0.2 second, what is the average force of the floor on the student?

• 1 × 10^–2 N

• 1 × 10² N

• 9 × 10² N

• 4 N

A force of 6.0 newtons changes the momentum of a moving object by 3.0 kilogram•meters per second. How long did the force act on the mass?

• 1.0 s

• 2.0 s

• 0.25 s

• 0.50 s

A 3.0-kilogram steel block is at rest on a frictionless horizontal surface. A 1.0-kilogram lump of clay is propelled horizontally at 6.0 meters per second toward the block as shown in the diagram below. Upon collision, the clay and steel block stick together and move to the right with a speed of

• 1.5 m/s

• 2.0 m/s

• 3.0 m/s

• 6.0 m/s

A 0.15-kilogram baseball moving at 20. meters per second is stopped by a catcher in 0.010 second. The average force stopping the ball is

• 3.0 × 10^–2 N

• 3.0 × 10⁰ N

• 3.0 × 10¹ N

• 3.0 × 10² N