The formulas are,
Impulse = mv-mu ....... (1)
v^2 = u^2 + 2as .......... (2)
We know that,
u=0
a=acceleration=gravity = 9.80665 m/s^2 = 9.81 m/s^2
s=19.6
sub (2) we get,
v^2 = 0+ 2*9.81*19.6
v^2 = 2*9.81*19.6
v^2 = 384.552
v = 19.6099
v = 19.61 m/s
Sub v=19.61 m/s in (1) we get,
Impulse = mv - mu
we know that u=0; v= 19.61 m/s; m= 3.00 kg
Impulse = 3(19.61) - 3(0)
Impulse = 58.83-0
Impulse = 58.83 Ns.
Therefore the gravitational force exerted by the stone is 58.83 Ns.
