Passage II
Figure 1 shows a model of an amusement park ride. At time = 0 sec, the cart is released from rest at Point P. It descends the tower toward Point Q and strikes the spring. As the spring is compressed, it slows the carts descent and eventually rebounds, sending the cart back up the tower. Frictional forces act on the cart whenever it is in motion, and the spring never extends above Point Q. Figure 2 shows computer simulations of the cart's height (the distance from ground level to the bottom of the cart), its velocity, and its acceleration during the first 20 sec of motion.
7. At approximately what time(s) during the 20 sec period, if any, does the cart touch the ground?
Your Answer is
Correct Answer is D
Explanation
Look at the picture of height in figure 2, the height is greater than 0 m at any time, so the cart has not reached the ground