Question

Time when ball again meets the lift:

• A. $\frac{5}{3}s$
• B. $\frac{4}{3}s$
• C. $\frac{3}{4}s$
• D. $\frac{3}{5}s$

Answer 1

The correct option is A $\frac{5}{3}s$

At the time when ball again meets the lift,
$S_L=S_B$
$\therefore 10t+\frac{1}{2}\times 2\times t^2=20t-\frac{1}{2}\times 10t^2$
Solving this equation, we get
$t=0$ and $t=\frac{5}{3}s$
$\therefore$ Ball will again meet the lift after $\frac{5}{3}s.$