Question

Find the velocity of the block when for the first time its acceleration becomes zero.

• A. 12.5 $m{s}^{-1}$
• B. 25 $m{s}^{-1}$
• C. 10 $m{s}^{-1}$
• D. None of these

Answer 1

The correct option is D None of these

$F_{max}=\mu N$

$=0.5\times 10\times 2$

$=10N$

$F_{net}=F-f$

$=20-2f-10$

$=10-2f$

$\Rightarrow a=5-t$

$\therefore V={\int }_0^{f}adt$

$=5t-\frac{t^2}{2}$

when $V=0$

$10t-t^2=0$

$\Rightarrow t=0,10$