posted by charlie on .
You pull on a rope that is attached to a box. The rope makes an angle of 25 degrees with the ground. You are pulling the box at a constant velocity. The force you are pulling with is 78N. The box weighs 25N. You pull the box a displacement of +16m.
What is the work done by you?
I got 7.25
What is the work done by friction?
What is the work done by the normal force?
I got 0
What is the work done by gravity?
can someone help me get the rest of this
How did you get 7.25? What are the dimensions of that number?
The answer is not 7.25 Joules. Multiply the horizontal force component by the distance the block moves. That is how to compute the work done.
The work done by friction is MINUS the work done by the person pulling.
The normal force and gravity do no work, since there is no motion in the vertical direction