Question

Two balls are dropped from same height at $ 1$ second interval of time. The separation between the two balls after $4 $ second of the drop of the $1^{\text {st }}$ ball is:

• A. 30 m
• B. 35 m
• C. 40 m
• D. 48 m

Answer 1

Answer: (B)

Motion of first ball $u=0, a=g, t=3$ sec.
We are consider that the $s$, is the distance covered by the
first ball in 4 seconds.
$s _{1}= ut +\frac{1}{2} gt ^{2}$
$0+\frac{1}{2} \times 10 \times(4)^{2}=80 m$
Let $s$, be the distance covered by the second ball in $2$ seconds.
$s_{2}=0+\frac{1}{2} \times 10 \times(3)^{2}=45 m$
Separation between the two balls.
$S _{1}- S _{2}=80 m -45 m =35 m$