Question

Finally, use the fact that when the vertical component of the position function is equal to zero, the object has landed, to find the time of flight. Choose the correct answer below.

A. The time of flight is the time when the vertical component of the position function is zero.

B. The time of flight is unrelated to the vertical component of the position function.

C. The time of flight is the time when the horizontal component of the position function is zero.

D. The time of flight is the total time elapsed during the motion.

Answer 1

The time of flight is determined by the vertical motion alone and is the time when the vertical component of the position function is zero. It is factually correct to state that this is the moment when the object lands back to its original launch level. Thus, choice A is the correct answer.

Step-by-step explanation:

The correct answer to the question is A: Time of flight is the time when the vertical component of the position function is zero. The time of flight for a projectile on a flat, horizontal surface occurs when it lands, which corresponds to the moment when its vertical displacement equals zero, indicating it has returned to the horizontal level from which it was launched.

Considering that the vertical motion determines the time of flight for a projectile, any other components such as the horizontal motion do not affect this time, since it proceeds at a constant velocity while the object is airborne.

In the GRASP CHECK, the correct answer is a. The time of flight would remain unchanged if the horizontal component of a projectile's velocity is doubled but the vertical component is the same.

This is because the time to reach the ground is exclusively governed by the vertical motion. Therefore, even if the project travels further horizontally due to the increased horizontal velocity, the time in the air won't be affected.