Question

A horizontal force of magnitude 356 N is employed to push a 78.0-kg block a distance of 18.6 m on a rough horizontal surface. If the block moves at a constant speed, (a) What is the work done by the 356-N force? (b) What is the coefficient of kinetic friction between the block and the rough surface?

Answer 1

Answer:

6621.6 Joule

0.46525

Explanation:

F = Force = 356 N

s = Displacement = 18.6 m

m = Mass of block = 78 kg

Work done

$W=F\times s\\\Rightarrow W=356\times 18.6\\\Rightarrow W=6621.6\ J$

The work done by the horizontal force is 6621.6 Joule

$F=\mu mg\\\Rightarrow \mu=\frac{F}{mg}\\\Rightarrow \mu=\frac{356}{78\times 9.81}\\\Rightarrow \mu=0.46525$

The coefficient of friction between the block and the rough surface is 0.46525