question_answer

A body of weight 50 N placed on a horizontal surface is just moved by a force of 28.2 N. The frictional force and normal reaction are

A) \[2N,3N\]

B)  \[5N,6N\]

C)  \[10N,15N\]

D)  \[20N,30N\]

Correct Answer: D

Solution :

 Frictional force,\[f=28.2\cos {{45}^{o}}\] \[=28.2\frac{1}{\sqrt{2}}=20\,N\] Normal reaction, \[R=50-28.2\text{ }sin\,{{45}^{o}}\] \[=50-20=30N\]