In the javelin throw at a track and field event, the javelin is launched at a speed of 29 m/s at an angle of 35° above the horizontal. As the javelin travels upward, its velocity points above the horizontal at an angle that decreases as time passes. How much time is required for the angle to be reduced from 35° at launch to 17°?

Answer 1

Solve for the time t when
Y(t)/X(t) = tan 17 = 0.3057

Y = 29 sin35 * t - (g/2)t^2
X = 29 cos35 * t

0.3057 = tan 35 - 0.20643 t

Take it from there.

Answer 2

1.911