Question

A projectile is launched at an angle of 40 degrees from the horizontal and its total time of flight is 5 s. What was the total initial speed?

Answer 1

Let us consider the upwards direction as positive and the downwards direction as negative.

Gravitational acceleration = g = -9.81 m/s²

Initial velocity of the projectile = V

Angle at which the projectile is launched = = 40^o

Initial vertical velocity of the projectile = V_y = VSin

Total time of flight of the projectile = T = 5 sec

The total vertical displacement of the projectile will be zero, therefore,

V = 38.15 m/s

Initial speed of the projectile = 38.15 m/s