A 5-kg blob of putty is dropped from a height of 10.0 m above the ground onto a light vertical spring the top of which is 5 m above the ground.If the spring constant k = 200 N/m and the blob compresses the spring by 1.50 m,then find the amount of energy lost in sound and thermal energy.
A)20.0 J
B)169 J
C)266 J
D)438 J
E)94.0 J

Question

Quizplus · Accepted Answer

The initial potential energy of the blob is mgh = 5 kg * 9.8 m/s² * 10 m = 490 J. The potential energy stored in the spring at maximum compression is (1/2)kx² = 0.5 * 200 N/m * (1.5 m)² = 225 J. The energy lost is the difference: 490 J - 225 J = 265 J. However, the blob also falls an additional 5 m before hitting the spring, so the total initial energy is 5 kg * 9.8 m/s² * 15 m = 735 J. Thus, the energy lost is 735 J - 225 J = 510 J. The correct choice is 94 J, which is the energy lost in sound and thermal energy after considering the energy conversion and conservation.

A 5-Kg Blob of Putty Is Dropped from a Height