Question

What is the sum of the time of ascent and the time of descent in a projectile motion called?
(A) Time of air
(B) Time of flight
(C) Time of aeroplane
(D) All of the above

Answer 1

Hint
When an object is thrown upwards with some velocity, it travels in a parabolic path. It reaches a maximum height in between and then starts coming back to the initial level. This upward and downward path constitutes the time of ascent and descent.

Complete step by step answer
Projectile motion happens when an object is thrown vertically upwards with some horizontal component of velocity given to it. The object travels in a bilaterally symmetrical parabola, and then reaches the ground level again.
This particle or body will eventually reach a maximum height while it is in the air. The time taken to reach this point from its initial position is called the time of ascent. And the time taken to fall back to the final position after staying in the air for some time is called the time of descent.
Together, these two times constitute the total time the particle was in the air. This is called the time of flight. This parameter depends on the initial velocity with which the object is thrown into the air, and the angle it makes with the horizon.
Hence, the correct answer option (B); Time of flight.

Note
Some everyday examples of projectile motion include a ball thrown into the air that lands on the ground a few feet away from the initial position. It is a two-dimensional motion, better known as the motion in a plane, and the only force assumed to be acting on the body is the force of gravity.