Answer to Question #306977 in Mechanics | Relativity for Aria

Question

A 30 kg block is pushed up an inclined plane at an angle of 25° with a constant velocity of 4 m/s by a force of 280 N parallel to the plane.

What is the coefficient of kinetic friction between the block and the plane?

Answer 1

Solution.

$m=30 kg;$

$\theta=25^o;$

$v=4 m/s;$

$F=280N;$

$\mu-?;$

$F=F_f+mgsin\theta;$

$N=mgcos\theta;$

$F_f=\mu N=\mu mgcos\theta;$

$F=\mu mgcos\theta+mgsin\theta;$

$\mu mgcos\theta=F-mgsin\theta;$

$\mu=\dfrac{F-mgsin\theta}{mgcos\theta};$

$\mu=\dfrac{280-30\sdot9.81\sdot0.4226}{30\sdot9.81\sdot0.9063}=0.58;$

Answer:$\mu=0.58.$