An object with a mass of 6kg is pushed along a linear path with a kinetic friction coefficient of uk(x)=1+cotx. How much work would it take to move the object over #x in [(pi)/12, (3pi)/8], where x is in meters?

1 Answer
Jul 20, 2017

The work is =128.7J

Explanation:

We need

cotxdx=ln|sin(x)|+C

The work done is

W=Fd

The frictional force is

Fr=μkN

The normal force is N=mg

The mass is m=6kg

Fr=μkmg

=6(1+cotx)gN

The work done is

W=6g38π112π(1+cotx)dx

=6g[x+ln|sin(x)|]38π112π

=6g((38π+lnsin(38π)))(112π+lnsin(112π)))

=6g(724π+1.27)

=6g(2.19)

=128.7J