Given the speed-time graph of a golf ball shot from ground at t = 0.
What will be the time of flight?
at t = 0, speed is 5 ms, this means, u = 5 ms. Also minimum speed is 3 ms. For a projectile speed is minimum and equal to its horizontal component at the highest point of its trajectory, as the vertical component is zero at this point. Let θ be the angle of projection, then,
u cos θ = 3
⇒ 5 cos θ = 3
⇒ cos θ = 35
θ = 53∘
∴ Time of flight = 2usinθg = 2×5×sin53∘10
⇒ 45s = 0.8s