Forces and Motion Review

A bus traveled 280 kilometers between two cities. It left the first city at 3:00 p.m. and arrived at the second city at 7:00 p.m. What was the average speed of the bus during the trip?

• 4 km/h

• 40 km/h

• 280 km/h

• 70 km/h

During which time interval was the object moving with the greatest average speed?

• 25 to 30 minutes

• 0 to 5 minutes

• 10 to 15 minutes

• 15 to 20 minutes

Which best explains why Clarence's statement about keeping his car at a constant velocity is wrong?

• The car track gave off heat.

• The car encountered air resistance.

• The speed of the car stayed the same.

• The direction of the car changed.

Zookeepers carry a stretcher that holds a sleeping lion. The total mass of the stretcher and lion is 175 kg. The lion's forward acceleration is 2 m/s². What is the force necessary to produce this acceleration?

• 177 N

• 350 N

• 87.5 N

• 0.011 N

Two forces act on a block as shown in the picture.

What is the net force on the block?

• 30 N to the left

• 30 N to the right

• 10 N to the left

• 10 N to the right

A student applied a force of 200 N to push a box 15 m down the sidewalk. Given the formula, W= F x d , how much work has been done?

• 3,000 J

• 300 J

• 30,000 J

• 30 J

To move a refrigerator, forces are applied as shown. Which of these statements best describes what will happen if the forces are applied at exactly the same time?

• The refrigerator will remain in place because the forces are not enough to move a refrigerator.

• The refrigerator will remain in the same place because the net force is zero.

• The refrigerator will move left because of the greatest force on the right.

• The refrigerator will move right because the force is over a greater surface area.

To complete a project, 200,000 Joules of work are needed. The time taken to complete the project is 20 seconds. How

much power is needed? Use Formula: Work = P = W / t

P= J/s

• 0.0001 J/s

• 200,020 J/s

• 1,000,000 J/s

• 10,000 J/s

An investigation is performed to determine how the angle of a ramp affects the speed of a ball as it rolls down the ramp. In addition to using the same ball and the same ramp, which of these should also remain constant?

• releasing the ball from the same position in each trial

• measuring the length of the ramp before each trail

• keeping the ramp at the same height for all trails

• keeping the ramp facing the same direction for all trials