A block of mass $10 \mathrm{~kg}$ placed on the rough horizontal surface having coefficient of friction $\mu=0.5$, if a horizontal force of $100 \mathrm{~N}$ acting on it then acceleration of the block will be:

• A

  $10 \mathrm{~ms}^{-1}$
• Correct answer
  B

  $5 \mathrm{~ms}^{-2}$
• C

  $15 \mathrm{~ms}^{-2}$
• D

  $0.5 \mathrm{~ms}^{-2}$

Solution

Here $f_{\max }=\mu N=\mu m g$ $=0.5 \times 10 \times 10=50 \mathrm{~N}$ $\Rightarrow a=\frac{\text { net force }}{\text { mass }}$ $=\frac{100-50}{10}=5 \mathrm{~m} / \mathrm{sec}^2$

Hence, the correct answer is option: 'B'.