Question

One body is dropped while a second body is thrown downwards with an initial velocity of $1m/s$ simultaneously. The separation between them is $1.8$ m after a time:

• A. $4.5s$
• B. $9s$
• C. $1.8s$
• D. $36s$

Answer 1

The correct option is A $4.5s$

Separation Between them $\left(d\right)=V\times T$,

where V and T are relative velocity and time respectively.

Here,

$d=18=2\times T$

$\Rightarrow T=18/2=9s$

Therefore, A is correct option.