Question
At a construction site, a 65.0 bucket of concrete hangs from a light (but strong) cable that passes over a light friction-free pulley and is linked to an 85.0box on a horizontal roof. The cable pulls horizontally on the box, and a 46.0 bag of gravel rests on top of the box. The coefficients of friction between box and roof are shown. The system is not moving.
Us=0.7
Uk=0.4
A. Find out the friction force on the bag of gravel.Express the answer using two significant figures.
B. Find out the friction force on the box.
C. Suddenly a worker picks up the bag of gravel. Use energy conservation to discover the speed of bucket after it has descended 1.80, from rest.