(h + .16) m g = 1/2 k x^2 total PE of block relative to where it stops
(h + .16) .82 * 9.8 = .5 * 120 * .16^2 PE released = PE of spring
8.04 h + 1.29 = 1.536
h = (1.536 - 1.29) / 8.04 = .031 m = 3.1 cm
Answer: Mass of the object is 75 kg.
So, according to the question:
distance = 90 miles
time = 1h 45min + 15 min + 1h = 3h
<span>The net force acting on the runner must be zero.</span>