What I Know
Multiple Choice. Select the letter of the best answer from among the given choices.

1. What is the force required to maintain an object at a constant velocity in a frictionless surface equal
to?
A. zero
B. the mass of the object
C. the weight of the object
D. the force required to stop it

2. When does an object undergo acceleration?
A. when it is changing direction B. when it is moving faster
C. when it is moving slower
D. all of these

3. A ball is thrown upwards and returns to the same location. When it turns, how much is the speed
compared with the initial speed?
A. half as much
B) the same
C. twice as much
D. four times as much
A

4. How does Galileo's interpretation of motion differ from Aristotle's? Galileo emphasized
A. rates of time
B. the acceleration of free fall
C. the role of distance in describing motion
D. none of these

5. From what you have learned from Galileo, what will happen if you roll a ball along a level surface?

A. keep rolling if friction is absent
B. roll as long as its inertia nudges It along
C. soon roll in the opposite direction
D. soon slow down due to its natural place

6. What is the straight-line motion caused by the gravitational pull of the earth?
A free-fall motion
B. horizontal motion
D. none of these
C. projectile motion

7. How does the acceleration of a stone thrown upward compare to the one thrown downward?
A. greater
B. smaller
C. the same
D. undetermined

8. What will happen to an object if no external forces act on it?
A. It will come to an abrupt halt.
B. It will continue moving at the same speed.
C. It will move slower and slower until it finally stops.
D. None of these

9. When no forces act on moving objects on-air, how can you describe their paths?
A. circles
B. ellipses
C. parabola
D. straight lines

10. Suppose you are riding a motorcycle, but it runs out of fuel while driving. The engine stops abruptly
but why don't you?
A. because of gravity
B. because of inertia
C. because of continuation principle
D. because of resistance

11. Suppose you are standing in the aisle of a moving bus. If the driver suddenly makes a left tum, wh
are you likely to lurch to the right? Because of
A. an equilibrium challenge
B. an unbalanced force
C. your momentum
D. your tendency to keep moving forward

12 Which of the following describes an object ?
A. object at rest
B. object in mechanical equulibrium
C.object in mechanical moving velocity
D. object moving slower

13. A ball along a horizontal surface maintains a constant speed Why is it so ?
A. friction is present
B. no inertia on the object
C. no the object horizontal on
D. surface is smooth

14. Why do a coconut and a bird's feather falling from a tree through the air to the ground below gain speed?

A. their velocity changes
B. there is a gravitational force acting on them
C.their inertia
D. their nature to become closer to the Earth

15. Which of the following is true about acceleration due to gravity ?
A. it is different for different objects in free fall
B. It is a fundamental property C. It increases in decreasing altitude
D. it is a universal constant​