The player kicks a football with an initial speed of v0 = 98 ft/s. Determine the two possible values for the angle of the kick, theta. The distance of the football field is 126 ft. Also determine the corresponding time at each of these two angles.

Answer 1

Range = Vo^2*sin2A/g = 126 Ft.
98^2*sin2A/32 = 126
98*2*sin2A = 4032
sin2A = 0.42
2A = 24.8o
A = 12.4o.

Or A = 180 - 12.4 = 167.6o.

Range = Xo * T = 126 Ft.
98*cos12.4 * T = 126
T = 1.32 s. = Time in air.

Tr = T/2 = 1.32/2 = 0.658 s.=Rise time.
= Time at 12.4o.

Tf = Tr = 0.658 s. = Fall time. = Time
at 167.6o.