(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A force, F, applied to a 12.1 kg crate at an angle (theta) of 41.0 degrees makes the crate move horizontally with a constant acceleration of 1.85 m/s^2. The coefficient of kinetic friction between the crate and the surface is uk=0.35. Calculate the magnitude of F.

2. Relevant equations

F = ma

Fx = F + friction + N + W = ma

Fy = F + friction + N + W = 0

uk*N = friction

so, F = mg(cos theta) - friction = ma

3. The attempt at a solution

I first found the force of kinetic friction, by multiplying the coefficient of kinetic friction (0.35) by the normal force (12.1 * 9.8), which equaled 41.5 N.

Then, I found m*a = (12.1 * 1.85) = 22.385.

I then set up the equation: F cos(theta) - friction = ma, or F(.7547) - 41.5 = 22.385

This gave me F = 84.65 N, which is wrong.

Can someone help me see where I'm going wrong?

Thanks!!

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# Homework Help: Calculating Force at an angle with kinetic friction coefficient

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