posted by Anthony on .
A football is kicked 66.6 meters. If the ball is in the air 5.39 s, with what initial velocity was it kicked?
Tr = Tf = 5.39/2 = 2.695 s.
Tr = Rise time.
Tf = Fall time.
Y = Yo + gt.
Y = 0 + 9.8*2.695 = 26.4 m/s = Final velocity when falling = Initial velocity
(Yo)when rising. Y=Ver. componenttg of velocity.
Range = Xo*(Tr+Tf) = 66.6 m.
Xo*(5.39) = 66.6
Xo = 12.36 m/s. = Hor. component of
tanA = Yo/Xo = 26.4/12.36 = 2.13592
A = 64.9o.
= Initial velocity.