A 13 kg box is placed at the top of a 4.5 m long, ramp inclined at an angle of 41 degrees (with the horizon). However, the ramp is covered with sand so the coefficient of friction is 0.19. How much time does it take the box to reach the bottom of the ramp?(adsbygoogle = window.adsbygoogle || []).push({});

Fgx=Fg sin=mg sin.

13kg (9.8 N/kg)=127N

127N Sin 41= 83N

Acceleration=83N/13kg=6.4m/s

4.5m=1/2 (6.4m/s)t^2

4.5m=3.2m/s t^2

t=1.19s

Im just confused as where the coefficient of friction comes into play, and how to solve it.

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# Homework Help: Unbalances and balanced forces

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