Question

A particle projected vertically upwards from the top of a tower with a certain speed strikes the ground in 9 seconds. The same particle thrown vertically downwards from the top of the same tower with the same speed as before strikes the ground in 4 seconds. Find the speed of projection and the height of the tower (g=10m/s)
ANS fast. No spam 50pts

Answer 1

Answer:

speed (u)= 25m per s. height (h)=180m

Explanation:

the object after going up, will come back down and have the same velocity as the 2nd ball that took 4sec. Therefore we can say that the ball that was thrown up was above the tower for 5sec.

Therefore, T=2u/g will give u (T=5)

and then use

h= ut + 1/2a(t)^2 for height of the tower.

Hope you understood.