So A rookie quarterback throws a football with an initial upward velocity component of 16.4 m/s and a horizontal velocity component of 19.8 m/s . Ignore air resistance. a) How much time is required for the football to reach the highest point of the trajectory? b) How high is this point? c) How much time (after it is thrown) is required for the football to return to its original level? d) How does this compare with the time calculated in part (a).

Question

So A rookie quarterback throws a football with an initial upward velocity component of 16.4 m/s and a horizontal velocity component of 19.8 m/s . Ignore air resistance. a) How much time is required for the football to reach the highest point of the trajectory? b) How high is this point? c) How much time (after it is thrown) is required for the football to return to its original level? d) How does this compare with the time calculated in part (a).
Express your answer using three significant figures. e) How far has it traveled horizontally during this time?

Henry · Answer

Xo = 19.8 m/s.
Yo = 16.4 m/s.

a. Y = Yo + g*Tr = 0, Tr = -Yo/g = -16.4/-9.8 = 1.67 s. = Rise time.

b. h = Yo*Tr + 0.5g*Tr^2.
g = -9.8 m/s^2.

c. T = Tr+Tf, Tf = Tr = 1.67 = Fall time.
T = Tr+Tr = 1.67 + 1.67 =

d. T = 2Tr.

e. d = Xo*T.