Friction acts in a direction the same as the direction of the object’s motion
false
15
Friction occurs when the surfaces of the two objects rub against each other
True
15
Friction causes moving objects to stop.
True
15
Friction is produced by a single object
False
15
Friction opposes motion of objects.
True
15
Friction is a (force, energy) that opposes the motion of objects.
force
15
Friction always acts (opposite, the same) the direction of the object’s motion
opposite
15
A ball rolled after being kicked and slowed down until it stopped. Which of the following forces caused the ball to slow down? A. electrical B. friction C. gravity D. magnetic
friction
15
Which of the following statements is TRUE? A. Friction makes objects move. B. Friction stops moving objects. C. Friction has no effect on moving objects. D. Friction allows moving object to continue moving.
B
15
What is the direction of gravity between two objects? A. sideways B. toward each other C. away from each other D. perpendicular to each other
B
15
Which object has the weakest gravitational pull? A. fist-sized rock B. piece of paper C. huge truck D. the moon
B
15
Which energy transformation occurs in a flat iron? A. electrical energy to heat B. mechanical energy to light C. chemical energy to sound energy D. chemical energy to electrical energy
A
15
What is always produced when there is energy transformation? A. chemical B. electricity C. heat D. light