Question

A particle projected vertically upwards with velocity u from ground is at height 75 metre at an interval of 2 seconds. Value of u is
(a) 40 m/s
(b) 45 m/s
(c) 35 m/s
(d) 30 m/s

Answer 1

Answer:

By using formula

v^2=u^2+2as

we can find the answer.

here, v=0, s=h, a=g.

.: u^2+2gh=0

.: u^2=-2gh

.: h=u^2/g.

Don't get confused with -ve sign. it indicates deceleration.