Question

force required to pull a body of 100 kg is 4kg-wt.. the coefficient of friction between the body and the surface is ​

Answer 1

a/c to question, force required to pull a body of mass 100kg is 4kg-wt.

let's find weight of body .

weight of body = mass of body × acceleration due to gravity.

= 100kg × 9.8m/s² = 980 N

and force is required to pull the body is 4kg-wt or 4 × 9.8 = 39.2 N

here it clear that weight of body is greater than force required to pull the body i.e., 980 N > 40N

so, here friction force is self adjusting force .

I mean, friction force must be equal to force required to pull the body.

i.e., friction = 4kg-wt = 39.2N

or, uN = 39.2 , here N is normal reaction acting between body and surface.

so, u × 980 = 39.2

or, u = 39.2/980 = 0.04

hence, coefficient of friction is 0.04