The change in velocity vector shown in the figure points in what direction? (Hint: see Figure 4-5.)
a. Tangent to the circle.
b. Pointing to the center of the circle.
c. Pointing away from the center of the circle.
d. Pointing perpendicular to the circle.
e. Always to the left.
Question 2
A girl whirls a ball on the end of a string above her head. Assume the motion of her hand to keep the ball in motion is negligible. For the ball to remain in a circular path while it rotates with a constant speed:
a. only the centripetal force shown in the figure is required.
b. in addition to the centripetal force shown in the figure, there must also be a force tangent to the motion of the ball.
c. in addition to the centripetal force shown in the figure, there must also be a centrifugal force that pulls the ball outward.
d. in addition to the centripetal force shown in the figure, there must also be a force radially inward from the string to cause circular motion.
e. the centripetal force inward and the centrifugal force outward must balance each other.