posted by jake on .
a football is thrown to a moving receiver .the football leaves the quarterback's hands 1.75m above the ground with a velocity of 17.0m/s[25deg]if the receiver starts 12.0m away from the quarterback along the line of flight of the ball when is is thrown , what constant velocity must she have to get to the ball at the instant it is 1.75 m above the ground ?
Vo = 17m/s[25o]
Xo = 17*cos25 = 15.4 m/s.
Yo = 17*sin25 = 7.2 m/s.
Y = Yo + g*t = 0 @ max. Ht.
Tr = -Yo/ g = -7.2/-9.8 = 0.73 s. = Rise
Tf = Tr = 0.73 s. = Fall time.
D = Xo*(Tr+Tf) = 15.4 * 1.46 = 22.5 m.