A force of 750 N is applied to a block of 100 kg to prevent it from sliding down an inclined plane of `30^(@)` inclination. If coefficients of static and kinetic friction are 0.4 and 0.2, the frictional force acting is :

Options

A. 750 N
B. 500 N
C. 350 N
D. 250 N

Answer

c

Explanation

Here `F = mu mg cos theta`
`= 0.4 xx 100 xx 10 xx(sqrt2)/(2)`
`= 200 xx 1.732 = 3.464 xx 10^(2)`
`= 350 N ("nearly") `
(c) is the choice.