A football is kicked at an 50 degree angle to the horizontal, travels a horizontal distance of 20m before hitting the ground. what is the initial speed?

Let u be the initial velocity, devide it into two component x and y the angle is 50 degree given so u in x direction = u cos50 in y direction = u sine50 time period = t = (2 u sine50) / g and horizontal distance = u cos50 * t (acceleration in x direction is zero) by putting the value of t in above eqn yuou will get s=ucos50 * (2 u sine50) / g 20 g = 2 u^2 cos50 * sine50 from here u can get the value of u which is initial velocity ...