Force + Motion

• a
• b
• c
• d

• a
• b
• c
• d

• a
• b
• c
• d

1.  A rope is attached to a block that has a weight of 120 N. When the rope exerts an upward force of 250 N on the block, what is the net force on the block?

• 370 N down
• 370 N up
• 130 N down
• 130 N up

1.  A car is parked on a flat driveway. Which of the following is a free-body diagram for this car?

• a
• b
• c
• d

1.  Four students push on a block of wood with the forces shown in the diagram below. Assume friction is negligible.The block slides horizontally. What is the net force acting on the block of wood?

• 3 N to the left
• 8 N to the left
• 11 N to the right
• 25 N to the right

1.  According to Newton’s law of universal gravitation, in which of the following situations does the gravitational attraction between two objects always increase?

• The masses increase, and the distance between the centers of mass increases.
• The masses increase, and the distance between the centers of mass decreases.
• The masses decrease, and the distance between the centers of mass increases.
• The masses decrease, and the distance between the centers of mass decreases.

1.  A ball is dropped from the top of a tall building. As the ball falls, the upward force of air resistance becomes equal to the downward pull of gravity. When these two forces become equal in magnitude, the ball will 

• flatten due to the forces. 
• fall at a constant speed. 
• continue to speed up. 
• slow to a stop.

1.  Which two factors determine the gravitational attraction between two objects?

• time and temperature
• shape and orbital speed
• color and texture
• mass and distance from the objects’ centers of mass 

10.  The diagram below shows a spinning water sprinkler. Water comes through a hose and is sprayed by the sprinkler.Which principle best explains why the sprinkler spins?

• Every action has an equal and opposite reaction.
• Solid substances are usually denser than liquid substances.
• . Energy is released when water condenses.
• Most substances expand when heated and contract when cooled.