A moving 8.07 kg block collides with a horizonal spring whose spring constant is 372 N/m. The block compresses the spring a maximum distance of 6.87 cm from its rest position. The coefficient of kinetic friction between the block and the horizontal surface is 0.752. (a) How much work is done by the spring in bringing the block to rest? (b) How much mechanical work is done by the force of friction while the block is being brought to rest by the spring? c) What was the speed of the block when it hit the spring? for this problem I don't know whether I should start with (a) or not, because the information from the other parts might be useful. I tried to solve (a) but I get the wrong answer. This is what I did. 1/2 kx^2=.5(372 N/m)(.0687)^2=0.8779 J. <--That is the wrong answer.