A gun which fires small balls of mass `20 g` is firing `20 balls` per second on the smooth horizontal table surface `ABCD`. If the collision is perfectly elastic and balls are striking at the centre of table with a speed of `5 m//s` at an angle of `60^(@)` with the vertical just before collision, then force exerted by one of the legs on ground is (assume total weight of the table is `0.2 kg`)

Options

A. `0.5N`
B. `1N`
C. `0.25N`
D. `0.75N`

Answer

B

Explanation

Force on table due to collision of balls
`F_("dynamic")=(dp)/(dt)=2xx20xx20xx10^(-3)xx5xx0.5=2N`
Net force on one leg `=1/4(2+0.2xx10)=1N`