work energy tipersa) the work done on the block by the hand. explain your reasoning. answer: iii,...
TRANSCRIPT
B > A = C = D
For A and C, there is no change in speed, hence no change in kinetic
energy and no work done. For D, the speed changes, but there is no change in kinetic energy (final K = initial K), so no work is done (negative
work from 15 s to 17.5 s is canceled by positive work from 17.5 s to 20 s). For B, the speed increases, as does the kinetic energy, so positive work is
done.
