Answer
See answers.
Work Step by Step
See the diagram. The view is from above. The car drives clockwise around the circle.
a. The car is speeding up. The tangential acceleration $a_T$ is in the same direction as its instantaneous velocity. There is a radial/centripetal acceleration $a_R$ that points toward the center of the circle. The net acceleration vector is labeled $a_{net}$.
b. The car is moving at constant speed. There is no tangential acceleration. There is a radial/centripetal acceleration $a_R$ that points toward the center of the circle. The net acceleration vector is the same as the radial acceleration.
c. The car is slowing down. The tangential acceleration $a_T$ is in the opposite direction as its instantaneous velocity. There is still a radial/centripetal acceleration $a_R$ that points toward the center of the circle. The net acceleration vector is labeled $a_{net}$.
