Work Up an Incline: Calculate Gravity, Friction & Push Work

[keemosabi]

Homework Statement

A 50 kg box is being pushed up an incline of 25 degrees, to a total height of 45 m. Kinetic friction between the box and the incline has a mew of .4.
a) What is the work done by gravity?
b)What is the work done by friction?
c) What is the work done by the person pushing the box.

Homework Equations

W = Fd

The Attempt at a Solution

For all of the parts, I am not sure what to use as my d. Do I use 45, or do i use (45/sin(45)), the hypotenuse and the distance that the box actually slides?

 

[LowlyPion]

Homework Statement

A 50 kg box is being pushed up an incline of 25 degrees, to a total height of 45 m. Kinetic friction between the box and the incline has a mew of .4.
a) What is the work done by gravity?
b)What is the work done by friction?
c) What is the work done by the person pushing the box.

Homework Equations

W = Fd

The Attempt at a Solution

For all of the parts, I am not sure what to use as my d. Do I use 45, or do i use (45/sin(45)), the hypotenuse and the distance that the box actually slides?

For changes in PE it's straight height difference.

For friction it's distance along the incline.

 

[keemosabi]

For changes in PE it's straight height difference.

For friction it's distance along the incline.

What about the work done by gravity? Is that height or distance on the incline? Or does it not matter.

 

[LowlyPion]

What about the work done by gravity? Is that height or distance on the incline? Or does it not matter.

Work by gravity is change in PE = m*g*h