Question

A body with a mass of 100kg accelerates down an inclined plane at an angle of 60 degrees. There is a friction involved in impeding this motion.

a. draw a free body diagram identifying all forces acting on the body.

b. show that the acceleration of the body can be calculated without the mass.

c. if the coefficient of kinetic friction is 0.05, determine the acceleration of the body.

Answer 1

answer

1

FBD can be drawn as

2

by 2nd law of newton

$mgsin\theta-f=ma$

$mgsin\theta-\mu mgcos\theta=ma\\a=g(sin\theta-\mu cos\theta)$

so acceleration is independent of mass of body

3.

by putting value

$a=9.8(sin60^0-(0.05)cos60^0)\\a=8.24m/s^2$