Answer to Question #288116 in Physics for Kev

Question

a 25 N block is pushed up a plane inclined 30° with the horizontal by a force F of 46 N applied parallel to the plane. The block moves 3.0 m up the plane. the coefficient of friction is 0.2 find the work done by: a. gravity b. force c. friction force d. normal force

Answer 1

a) The work done by gravity:

$$W=mgh=75\text{ J}.\\$$

b) The work done by force:

$$W=Fd=F\dfrac h{\sin30°}=276\text{ J}.$$

c) The work done by friction:

$$W=\mu mg\cos30°=4.33\text{ J}.$$

d) The work done by the normal force is 0.