A block of mass `10kg` is kept on a rought floor .The coefficient of friction between floor and block are `mu_(s)= 0.4` and `mu_(k) = 0.3` forces` F_(1) = 5 N` and `F_(2) = 4 N` are applied on the block as shown in figure

If `F_(1) = 5N` and `F_(2) = a N` for what maximum value of a the motion of block impenride?

Options

A. `sqrt(1557)N`
B. `sqrt(1225)N`
C. `sqrt(1664)N`
D. `sqrt(875)N`

Answer

a

Explanation

Now appling force will be equal to maximum friction force
`i.e. sqrt(3^(2)+ a^(2)) = f_(1) = 40`
`rArr a = sqrt(1557) N`