A ball is gentle dropped from a height of 20m. If its velocity increases uniformly at the rate of 10 ms-2, with what velocity will it strike the ground? After what time will it strike the ground?
s = 20m
u = 0m/s
a = 10m/s2
Using third law of motion
v2 = u2+2as
v2 = 02 + 2(10)(20)
v2 = 400
v = 20m/s
Also, using first law of motion
v = u + at
20 = 0+10t
t = 2 sec