question_answer

A block of mass \[2kg\] is placed on the surface of a trolley of mass \[20kg\] which is on a smooth surface. The coefficient of friction between the block and the surface of the trolley is\[0.25\]. If a horizontal force of \[2N\] acts on the block, the acceleration of the system in \[m{{s}^{-2}}\] is\[(g=10m{{s}^{-2}})\]

A) \[1.8\]                                  

B) \[1.0\]

C) \[0.9\]                                  

D) \[0.09\]

Correct Answer: D

Solution :

The force of limiting friction between the block and trolley Since,    \[F=2N,\,\,F<{{f}_{L}}\] So, both will move together with acceleration \[{{a}_{B}}={{a}_{T}}=\frac{2}{20+2}=\frac{1}{11}=0.09\,\,m/{{s}^{2}}\]