Question

In ideal projectile motion, when the positive y -axis is chosen to be vertically upward, the y -component of the acceleration of the object during the ascending part of the motion and the y -component of the acceleration during the descending part of the motion are, respectively,

a) positive, negative.
b) negative, positive.
c) positive, positive.
d) negative, negative.

Answer 1

In ideal projectile motion with the positive y-axis upwards, the y-component of acceleration is consistently negative, -9.8 m/s², during both ascending and descending parts of the motion. (Option d)

Step-by-step explanation:

In ideal projectile motion, the acceleration due to gravity is always directed downwards toward the Earth, regardless of whether the object is ascending or descending. Thus, when the positive y-axis is chosen to be vertically upwards, the y-component of the acceleration is negative in both the ascending and descending parts of the motion, indicating that gravity is acting in the opposite direction to the upward motion.

The y-component of acceleration of an object experiencing projectile motion under the influence of gravity alone is -9.8 m/s², which remains constant throughout the projectile's flight. This means that for the given options, the correct answer is d) negative, negative, as the acceleration due to gravity is consistently acting downward whether the object is rising or falling.