Question

A football is kicked straight up into the air; it hits the ground 3.6 s later.

Part A What was the greatest height reached by the ball? Assume it is kicked from ground level. Express your answer with the appropriate units. ymax ymax = nothingnothing SubmitRequest Answer Part B With what speed did it leave the kicker's foot?

Answer 1

Let us assume that the initial speed is u. And so, after time t, the velocity is
  
And the height climbed is
   
And so, when the ball comes back, then y = 0. So, the time at which it comes back to the initial position is
   
  
So, the time at which the object reaches the highest position is
  
And so, at this time the height is
   
   
   
   
And so, for the given values,
   T = 3.6 s, g = 9.8 m/s^2, we have
  
  

Part B :
   As
  
so,
   
so, the initial speed is