Question

a stone is projected vertically upwards with a velocity of 30 m/s from the ground calculate
(1)the time taken to attain maximum height
(2)the time of flight
(3)maximum height reached

Answer 1

Answer:

1. 3sec. 2. 6s. 3. 45m

Explanation:

1. u=30

a= -g

v= 0

so, v=u +at

0=30 -gt

30=gt

t=30/g = 30/10 = 3s

2. total time is equal to ascent +descent that is

3+3 = 6s

3. v²-u²= 2gh

0 - 900 = 2 x -10 x h

-900/-20= 45m