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

A 68 kg crate is dragged across a floor by pulling on a rope attached to the crate and inclined 17° above the horizontal. (a) If the coefficient of static friction is 0.45, what minimum force magnitude is required from the rope to start the crate moving? (b) If μk = 0.39, what is the magnitude of the initial acceleration (m/s^2) of the crate?

2. Relevant equations

Equations of static and kinetic friction; Newton's Second Law.

3. The attempt at a solution

I managed to answer the first question and it was true. The value is 277.66 N. The second part, I have a problem with:

So, after the crate starts moving, a kinetic friction is present. F(kinetic) = μk * N, where N = mg - F(min)sin@ (previous part). The answer is 228.23. Then according to Newton's law, Fcos@ - f(kinetic) = ma. We computeaand the answer is 0.54. But the website is saying perpetually that the answer is wrong. What did I do wrong?

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# Homework Help: Static/kinetic friction problem

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