# Mastering Physics

## Answers and Replies

A factory worker pushes a 29.3 crate a distance of 5.00 along a level floor at constant velocity by pushing downward at an angle of 31.4 below the horizontal. The coefficient of kinetic friction between the crate and floor is 0.250 .

A) What magnitude of force must the worker apply to move the crate at constant velocity?
Take the free fall acceleration to be .

B) How much work is done on the crate by this force when the crate is pushed a distance of 5.00 ?
Take the free fall acceleration to be .

c) How much work is done on the crate by friction during this displacement?
Take the free fall acceleration to be .

D) How much work is done by the normal force?

E) How much work is done by gravity?

F) What is the total work done on the crate?

No-one will help you if you have not made an attempt to do the problem yourself.

i have no idea where to even start?

Just try to grasp the relevant theory. How do we define work? What is friction? What is the equation for friction? etc. Then try to make an attempt to solve it, it's not so difficult.

Last edited:
i tried doing 29.3*9.8*.25, anddd then i got 71.785

andd then i did 71.785cos(31.4) and it was wrong and for d n e i got o, i cannot ddddddddddddddddddo the rest

cristo
Staff Emeritus
Science Advisor
i tried doing 29.3*9.8*.25, anddd then i got 71.785

andd then i did 71.785cos(31.4) and it was wrong and for d n e i got o, i cannot ddddddddddddddddddo the rest

What part of the question are you attempting? And where did the numbers come from? Please show your working properly (and that means algebraic equations, not just numbers); otherwise, it's very hard to help you!

Try drawing a diagram.