Water droplets are coming from

Question:

Water droplets are coming from an open tap at a particular rate. The spacing between a droplet observed at $4^{\text {th }}$ second after its fall to the next droplet is $34.3 \mathrm{~m}$. At what rate the droplets are coming from the tap ? (Take $\mathrm{g}=9.8 \mathrm{~m} / \mathrm{s}^{2}$ )

  1. 3 drops / 2 seconds

  2. 2 drops / second

  3. 1 drop / second

  4. 1 drop $/ 7$ seconds


Correct Option: , 3

Solution:

In 4 sec. $1^{\text {st }}$ drop will travel

$\Rightarrow \frac{1}{2} \times(9.8) \times(4)^{2}=78.4 \mathrm{~m}$

$\therefore 2^{\text {nd }}$ drop would have travelled

$\Rightarrow 78.4-34.3=44.1 \mathrm{~m}$

Time for $2^{\text {nd }}$ drop

$\frac{1}{2}(9.8) \mathrm{t}^{2}=44.1$

$t=3 \mathrm{sec}$

$\therefore$ each drop have time gap of $1 \mathrm{sec}$

$\therefore 1$ drop per sec

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