Question

A gun is fired with a velocity of 150m|s at an angle of 30°to the horizontal calculate its time of flight

Answer 1

The time of flight is given as follows (see https://courses.lumenlearning.com/boundless-physics/chapter/projectile-motion/):

$$t = \dfrac{2u\sin\theta}{g}$$

where $u = 150m/s$ is the initial speed, $\theta = 30\degree$ is the launch angle, $g = 9.8m/s^2$ is the gravitational acceleration. Thus, obtain:

$$t = \dfrac{2\cdot 150m/s\cdot \sin30\degree}{9.8m/s^2} \approx 15s$$

Answer. 15s.