Afootball 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

Amplify and switch electrical power and electronic signals

The correct choice is c