Posted by Lauren01 on Wednesday, February 22, 2012 at 12:07pm.
A ball is released from a tower at a height of 100 meters toward the roof of another tower that is 25 meters high. The horizontal distance between the two towers is 20 meters. With what horizontal velocity should the ball be imparted so that it lands on the rooftop of the second building?

physics  Henry, Thursday, February 23, 2012 at 6:46pm
h = Yo*t + 0.5g*t^2 = 100  25 = 75 m.
o + 4.9t^2 = 75.
t^2 = 15.31 m.
Tf = 3.91 s. = Time to fall to roof.
Dx = Xo * Tf = 20 m.
Xo * 3.91 = 20.
Xo = 20 / 3.91 = 5.11 m/s. = hor. velocity.