question_answer

A block of mass \[10\,\,kg\] is placed on a rough horizontal surface whose coefficient of friction is 0.5. If a horizontal force of \[100\,\,N\] is applied on it, then acceleration of block will be:

A) \[10\,\,m/{{s}^{2}}\]                     

B) \[5\,\,m/{{s}^{2}}\]

C)  \[15\,\,m/{{s}^{2}}\]                    

D)  \[0.5\,\,m/{{s}^{2}}\]

Correct Answer: B

Solution :

Force that produces acceleration is                 \[F'=F-\mu R\] Given,   \[F=100\,\,N,\]                  \[F=\mu R=0.5\times 10\times 10\] \[\therefore \]  \[F'=100-50=50\,\,N\] Also, acceleration\[=\frac{F'}{m}=\frac{50}{10}=5\,\,m/{{s}^{2}}\]