Answer:
4.9 J
Explanation:
From hook's law,
The work done in stretching a spring is given as,
E = 1/2F×e.................... Equation 1
Where E= Wok done, F = force on the spring, e = extension.
Note: from the question, The force on the spring is the weight of the collar on the spring, Therefore,
F = W.
Then,
E = 1/2W×e................. Equation 2
Given: W = mg = 2×9.8 = 19.6 N, e = 0.8-0.3 = 0.5 m
Substitute into equation 2
E = 1/2(19.6)(0.5)
E = 4.9 J.
Hence the work done by the collar = 4.9 J
