Question

A particle is thrown in upward direction velocity is not given. Find out the displacement of the paticle in last sec in upward journey?

Answer 1

Explanation:

Let u & H be initial velocity and maximum height respectively so, u=2gH

Now, for both time t1 & t2 displacement is h

h=ut−21gt2

t2+g2ut+g2h=0

which is having two roots t1and t2

t1+t2=g2uort1+t2=g22gH

⇒H=8g(t1+t2)2