Question

A person standing on the roof of a building 30m high drops a ball vertically downwards with an initial velocity of 500cm/s.Acceleration due to gravity is 9.8m/s2.(a) What will be the velocity of ball after 0.5s?(b)Where will be the ball after 1.5s?(c)What will be the velocity of the ball while striking the earth?

Answer 1

(a)h=5m
h=1/2gt²
t=√2h/g
=√2*5*9.8
t=√98=9.89

(b) h=1/2gt²
height after 1.5 sec
=0.5*9.8*2.25
=11.02
hence height from the roof =30-11.02=18.98

Answer 2

Answer.

u=500cm/s =5m/s

(a). t = 0.5s

v = u + gt

Put the values then u get ur answer.

(b) t = 1.5

u= 5 m/s

S= ut+ 1/2 gt2

Then put the values in that formula