The answer is below.
Work Step by Step
a) The reading is 0g when the phone is in free fall. Thus, we see that the phone is in free fall for .5 seconds (between .6 and 1.1 seconds). b) The sharp peaks represent when it bounces. Thus, it bounced twice. c) The maximum net force is at the peaks, so it is: $=2gw+gw=3gw$ d) It returns to rest when the reading returns to 1g, which occurs at t=1.6 seconds.