Question

A body is projected with a velocity 30 ms power -1 reaches maximum height in 1.5 seconds. Find the angle of projection at its initial point.

Answer 1

Explanation:

Initial velocity= u = 30m/s

It is said that the body reaches maximum height at 1.5 s

We know the time of flight of the whole projectile to be 2usintheta/g

Therefore for half of the projectile or at the maximum height = usintheta/g

Therefore putting values,

=> 30sintheta/g=1.5. (taking g= 10m/s^2, you can also put 9.8)

=> sin theta = (1.5×10)/30

=> sin theta=1/2

SIN THETA= SIN 30

THEREFORE ANGLE OF PROJECTION IS 30°