Answer to Question #174247 in Physics for ghazal

Question #174247

a box drops down from a lorry while moving with a speed of v zero on the road with inclination θ°, where the mass of the box and kinetic friction coefficient and me and u, respectively. for the moment that the box slides up and reaches a possible maximum height(L).

(a) what is work done done by friction?

(b)what is work done by gravity?



1
Expert's answer
2021-03-23T11:10:58-0400

The initial kinetic energy of the box:


EK=12mv2.E_K=\frac12 mv^2.

This energy is wasted to move up the incline (acquire potential energy) and to overcome friction. Assume the maximum height is H above the horizontal:


EP=mgH,W=μmgx=μmgHsinθ.E_P=mgH,\\ W=\mu mgx=\mu mg\frac{H}{\text{sin}\theta}.

According to conservation of energy:


EK=EP+W, 12mv2=mgH(1+μsinθ), H=v2 sinθ2g(sinθ+μ). W=μmhv22(sinθ+μ).E_K=E_P+W,\\\space\\ \frac12 mv^2=mgH\bigg(1+\frac{\mu}{\text{sin}\theta}\bigg),\\\space\\ H=\frac{v^2\text{ sin}\theta}{2g(\text{sin}\theta+\mu)}.\\\space\\ W=\frac{\mu mhv^2}{2(\sin\theta+\mu)}.


Need a fast expert's response?

Submit order

and get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!

Comments

No comments. Be the first!

Leave a comment