What term describes a change in the speed of an

20. What term describes a change in the speed of an object in circular motion?
A. centrifugal force B. centripetal acceleration C. centripetal force D. tangential speed
Numbers 21-25
21. In a parking lot a rabbit across on which a set of coordinate axes has been formulated. Given is the rabbit’s
position in meters as a function of time in seconds.
x = -0.31 t 2 + 7.2 t + 28
y = 0.22 t
2
-0.91t + 30
What is the rabbit’s position vector in unit vector notation?
22. What is the magnitude of angle notation?
0
23. What i s the rabbit’s velocity v at time t = 15 s? 24. What is the angle of velocity?
A. -100 0 B. -130 0 C. 100 0 D. 130 0
25. What is the acceleration a at time t= 15s?
2
26. A ball rolls off the edge of a table. The horizontal component of the ball's velocity remains constant during its
entire trajectory because
27. A monkey is sitting at the top of a tree 20 m high from the ground level. A person standing on the ground
wants to feed the monkey. He uses a bow and arrow to launch the food to the monkey. If the person knows
that the monkey is going to drop from the tree at the same instant that the person launches the food, how
should the person aim the arrow containing the food?
28. An athlete throws a ball with a velocity of 40 m/s at an angle of 20e above the horizontal. Which of the
following statements is true in this case?
A. The vertical component of the velocity remains constant.
B. The horizontal component of the velocity changes.
C. The vertical component of the velocity changes sign after the ball attains its maximum height.
D. The horizontal component of the velocity changes sign after the ball attains its maximum height.