An object with a mass of 6 kg6kg is pushed along a linear path with a kinetic friction coefficient of u_k(x)= 2+sinx uk(x)=2+sinx. How much work would it take to move the object over #x in [2, 5], where x is in meters?

1 Answer
Jul 19, 2017

The work is =311.7J=311.7J

Explanation:

We need

intsinxdx=-cosx+Csinxdx=cosx+C

The work done is

W=F*dW=Fd

The frictional force is

F_r=mu_k*NFr=μkN

The normal force is N=mgN=mg

The mass is m=6kgm=6kg

F_r=mu_k*mgFr=μkmg

=6(2+sinx)g=6(2+sinx)g

The work done is

W=6gint_(2)^(5)(2+sinx)dxW=6g52(2+sinx)dx

=6g*[2x-cosx]_(2)^(5)=6g[2xcosx]52

=6g((10-cos5)-(4-cos2))=6g((10cos5)(4cos2))

=6g(6-cos5+cos2)=6g(6cos5+cos2)

=6g(*5.3)=6g(5.3)

=311.7J=311.7J