How to find Velocity Inital with just angle and time?

[ktmjake1107]

1. A football i kicked from a platform at an angle of 55 degrees. The time from its inital kick to where it landed was 2.3 seconds.

t= 2.3s
vi= ?
max y=?
change in x=?
angle= 55


2. I do not know what equtaion to use on this problem?

 

[willem2]

Just assume the initial speed of the ball is equal to v.
You can split the problem in a vertical and a horizontal direction
solve the vertical problem first to find out what v must be to make the ball return to Earth in 2.3 s