A very large number of balls are thrown ve

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A very large number of balls are thrown vertically upwards in quick succession in such a way that the next ball is thrown when the previous one is at the maximum height. If the maximum height is $5\,m$, the number of ball thrown per minute is (take $g = 10\,m{s^{ - 2}}$)

A

$120$

B

$80$

C

$60$

D

$40$

A very large number of balls are thrown vertically upwards in quick succession in such a way that the next ball is thrown when the previous one is at the maximum height. If the maximum height is $5\,m$, the number of ball thrown per minute is (take $g = 10\,m{s^{ - 2}}$)

Maximum height of ball $= 5 \,m$

So velocity of projection $ \Rightarrow u = \sqrt {2gh} $$ = 10\;m/s$

Time interval between two balls (time of ascent)

$ = \frac{u}{g} = 1\;sec = \frac{1}{{60}}\,min$.

So number of ball thrown per min. $= 60$