1. Which of the following pairs of quantities have the same SI units?
a. force and mass
b. none of the choices
c. force and acceleration
d. weight and mass
e. force and weight
2. In which case would the net force on the object equal zero?
a. the object is moving at a constant velocity of 25 m/s (north)
b. the object is moving at a constant velocity of 25 m/s (north) and the object is traveling in a circle at a constant speed of 25 m/s
c. the object is at rest
d. the object is at rest and the object is moving at a constant velocity of 25 m/s (north)
e. the object is traveling in a circle at a constant speed of 25 m/s
3. Many cars have ABS, or anti-lock braking systems, which prevent the tires from skidding during hard braking, and thus stop the car in a shorter distance. How is this possible?
a. it uses static friction between the tires and road, which is greater than kinetic friction.
b. it uses static friction between the tires and road, which is less than kinetic friction.
c. it uses kinetic friction between the tires and road, which is less than static friction.
d. it uses both static and kinetic friction between the tires and road.
e. it uses kinetic friction between the tires and road, which is greater than static friction.
4. A physics student has a pair of fuzzy dice hanging from the rearview mirror of her car. In which case would the dice swing forward?
a. the car is accelerating backward.
b. the car is accelerating forwards.
c. the car is moving forward at a constant velocity.
d. the car is traveling in a circle at a constant speed.
e. the car is moving backward at a constant velocity.
5. Which is true if the velocity of an object is changing?
a. there must be friction acting on the object.
b. the object cannot be traveling in a circle.
c. the net force on the object must be non zero.
d. the net force on the object must be zero.
e. there must be no friction acting on the object.
6. Two large boxes, A and B, are at rest on a frictionless floor. The boxes are identical in all ways, except that the mass of box A is ten times that of box B. Which statement is true?
a. no force is needed to accelerate the boxes across the floor since it is frictionless.
b. box A is ten times harder to accelerate across the floor than box B.
c. both boxes are equally hard to accelerate across the floor.
d. box B is ten times harder to accelerate across the floor than box A.
e. the mass of each box must be known to determine the answer.
7. Two moving objects, A and B, have equal accelerations but different masses. If the mass of object A is greater than that of object B, which is true about the net force on each object?
a. the net force on object B is greater than the net force on object A.
b. the mass of each object must be known to determine the answer.
c. the net force on object A is greater than the net force on object B.
d. the net force on each object is equal since the acceleration is equal.
e. the net force on each object is zero.
8. A 1.0 kg object has a weight of 9.8 N, while a 10.0 kg object has a weight of 98 N. How do their accelerations compare while in free fall? (ignore air resistance)
a. the distance fallen must be known to determine the acceleration.
b. the 10.0 kg object has less acceleration since it has more mass.
c. the 10.0 kg object has more acceleration since it has more weight.
d. the acceleration of each object is the same.
e. the objects do not accelerate, but fall at a terminal speed.
9. Identical cars A and B are traveling at the same speed as they go around two different curves. If car A goes around a curve of radius 50 m, while car B goes around a curve of radius 100 m, how does the centripetal force on each compare?
a. the centripetal force on car A is equal to that on car B.
b. the centripetal force on car A is twice that on car B.
c. the centripetal force on car A is four times that on car B.
d. the centripetal force on car A is one half that on car B.
e. the centripetal force on car A is one quarter that on car B.
10. At the same instant that a cannonball is shot horizontally a baseball is dropped from the same height. How does the vertical acceleration of each ball compare while falling? (Ignore air resistance)
a. the mass of each ball is required to determine its acceleration.
b. the acceleration of the cannonball is greater than the baseball.
c. the speed of the cannonball is required to determine its acceleration.
d. the acceleration of the cannonball is less than the baseball.
e. both balls have the same acceleration.
11. According to Newton's third law of motion, when object A exerts a force on object B, then object B exerts the same force back on object A. Why do these forces NOT cancel each other out?
a. the force from object B is actually a little larger than the force back from object A.
b. the forces act on different objects.
c. the mass of objects A and B is different.
d. the force from object A is actually a little larger than the force back from object B.
e. the forces act in opposite directions.
12. When a physics student kicks an unmoveable brick wall he hurts his toe, as explained by Newton's third law of motion. However, when he kicks a soccer ball it moves. Is Newton's third law still valid in this case?
a. No, the force from the toe is just a little larger than the force back from the ball.
b. Yes, the force from the toe is still equal to the force back from the ball.
c. Maybe, depending on the speed of the kick.
d. No, the force from the toe is actually much larger than the force back from the ball.
e. Maybe, depending on the mass of the ball.
13. An apple is hanging stationary from a branch of a tree. The Earth pulls down on the apple, so according to Newton's third law,
a. the apple pulls up on the Earth.
b. the branch pulls up on the apple.
c. the tree pulls up on the branch.
d. the branch pulls down on the tree.
e. the apple pulls down on the branch.
14. The force of gravity on a satellite is 200 N when it is at a given distance from Earth. What is the force of gravity on the satellite if it moves towards Earth so its distance is now one half the original distance?
a. 200 N
b. 50 N
c. 100 N
d. 800 N
e. 400 N
15. What would happen to your weight if the mass of the Earth was suddenly doubled?
a. it would be one half its original value.
b. it would be one quarter its original value.
c. it would remain unchanged.
d. it would be twice its original value.
e. it would be four times its original value.