A block of weight 5 N is pushed against a vertical wall by a force 12 N. The coefficient of friction between the wall and block is `0.6`. Find the magnitude of the force exerted by the wall on the block :

Options

A. 12 N
B. 5 N
C. 7.2 N
D. 13 N

Answer

D

Explanation

(d) N=applied force =12N
`therefore " " f_("max")=mu N=7.2N`
since weight `w lt f_("max")`
Force of friction f=5N
`therefore` Net contact force`=sqrt(N^(2)+f^(2))=sqrt((12)^(2)+(5)^(2))=13 N`