Answer:
77.05N of force
Explanation:
Detailed explanation and calculation is shown in the image below
When the spring is stretched by 15.2 cm = 0.152 m, the spring exerts a restorative force with magnitude (due to Hooke's law)

where
is the spring constant. Solve for
.

The amount of work required to stretch or compress a spring by
from equilibrium length is

Then the work needed to stretch the spring by 15.2 cm is

and by 15.2 + 13.7 = 28.9 cm is

so the work needed to stretch from 15.2 cm to 28.9 cm from equilibrium is

we can reduce the friction between its moving parts.
Answer:
(a) 98.548 mPa
(b) N = 942346
9.42 X 10∧5 cycles
Explanation:
The solved solution is in the attach document.