Question

A ball is thrown vertically upwards. It is
at the same height h after 10 seconds and
20 seconds. Then the value of h is (assume g = 9.8 m/s2)
​

Answer 1

Answer

v = u+at

v = 0 m/s, a

= -10 m/s^2

= 6/2 = 3s.

0 = u - 10 x 3

0 = u - 30

u = 30 m/s

s = ut + 1/2 at^2

s = 30 x 3 + 1/2 x -10 x 9

s = 90 - 45

s = 45 m

**45**Velocity of the ball thrown is 30 m/s.

Answer 2

hey...your answer

v = u+at

v = 0 m/s, a

= -10 m/s^2

= 6/2 = 3s.

0 = u - 10 x 3

0 = u - 30

u = 30 m/s

s = ut + 1/2 at^2

s = 30 x 3 + 1/2 x -10 x 9

s = 90 - 45

s = 45 m

Velocity of the ball thrown is 30 m/s.