Answer to Question #343560 in Mechanics | Relativity for John

Question

A crate has a mass of 42 kg is placed on an 50° incline surface. The coefficient of friction between the crate and the surface is 0.85. If the crate is pushed down the incline at a rate of 2.25 m/s², determine:

a) the normal force 

 

b) the frictional force 

c) the pulling force P 

Answer 1

a)

$N=mg\cos 50°=270~N,$

b)

$F=\mu N=230~N,$

c)

$P=m(g+a)(\sin 50°-\mu \cos 50°)=95~N.$