Question

A block of mass m is kept on the rough horizontal surface the coefficient of static friction between the block and the surface is new the block is to be pulled by applying the force to it the minimum force is needed to slide the block is

Answer 1

Answer:

yes

Explanation:

block will not pulled by minimum force because his weight is more there is need more force to pulled it .

Because of due to rough surface.

Answer 2

We can from a free body diagram prove that minimum force required is F = x m g/(cos@ + x sin @)----(a)

(Let's suppose mew= x and angle theta of applied force be @)

For F to be minimum denominator in (a) must be maximum i.e. 1

differentiating the denominator as (cos@ + x sin@ = 1 )

we can get tan@ = x

and also sin@ = x/((1+x^2)^(1/2)) cos@= 1/(1+ (x^2))^(1/2)

substituting the values of sin @ and cos @ in ( a) we get FINALLY F= x m g/((1+x^2)^(1/2))

SORRY FOR MAKING SO COMPLICATED WRITING HOPE U UNDERSTAND AFTER SMALL EFFORT