An object with a mass of 6kg is pushed along a linear path with a kinetic friction coefficient of uk(x)=1+5cotx. How much work would it take to move the object over x[5π12,5π8], where x is in meters?

1 Answer
Feb 25, 2018

The work is =25.28J

Explanation:

Reminder :

cotxdx=ln(|sinx|)+C

The work done is

W=Fd

The frictional force is

Fr=μkN

The coefficient of kinetic friction is μk=(1+5cot(x))

The normal force is N=mg

The mass of the object is m=6kg

Fr=μkmg

=6(1+5cot(x))g

The work done is

W=6g58π512π(1+5cot(x))dx

=6g[x+5ln(|sinx|)]58π512π

=6g(58π+5ln(sin(58π)))(512π+5ln(512π)))

=6g(0.43)

=25.28J