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- Homework Statement
- A 4.9 kg mass slides 3.6 m up a frictionless 35 degree incline. How much work is done by gravity?

I keep getting this question incorrect and I don't know what I'm doing wrong.

- Relevant Equations
- W= F*d*cos(theta)

first I tried to use gravitational force to solve it but because of the incline the gravitational force is zero. so I used normal force to solve.

Normal force is 39.36,

then f*d*cos(theta)

39.36*3.6*cos(55)

it would be cos 55 because the angle is in the direction of normal force from the position of the object

it would equal= 39.36*3.6*cos(55)= 81.27

but it is incorrect.

can anyone please tell me where I made a mistake or if there is another way I should be solving this problem?

thanks

Normal force is 39.36,

then f*d*cos(theta)

39.36*3.6*cos(55)

it would be cos 55 because the angle is in the direction of normal force from the position of the object

it would equal= 39.36*3.6*cos(55)= 81.27

but it is incorrect.

can anyone please tell me where I made a mistake or if there is another way I should be solving this problem?

thanks