The questin is a 5kg box slides down a frictionless plane. The plane makes an angle of 15 degrees with the horizonal and has a length of 2.00 meters.(adsbygoogle = window.adsbygoogle || []).push({});

a) if the boxs starts from rest calculate the acceleration

b) calculate the speed when the box reaches the bottom of the incline

I did draw a picture.

I have w = mg which is w 5(9.80) = 49 N

Wx = sin 15 *49 = 12.68 N Wy = cos 15 * 49 = 47.33 N

To determine the accel i used the formula A=F/m

A= 12.68 N /5kg = 2.53m/s

D = 1/2 AT^2 2*2.53*t^2 = 1.26 secoinds

Vf^2 = Vi^2+2AD =Vf^2 = 2*2.53* 2 by the way Vi = 0 since it started from rest

Vf = 3.18m/s

Is this right?

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# Homework Help: Hw problem

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