Question

A baseball is hit high and far. Which of the following options is true? At the highest point,

(a) the magnitude of the acceleration is zero.

(b) the magnitude of the velocity is zero.

(c) the magnitude of the velocity is the slowest.

(d) more than one of the above is true.

(e) none of the above is true.

Short answer

At the highest point, the magnitude of the ball’s velocity is the slowest.

Step-by-step solution

Step 1. Meaning of projectile motion

A particle's projectile motion refers to the 2-D motion of the particle that is given an initial velocity and launched into the air at a particular angle. In the case of projectile motion, the only force acting upon the particle is the gravitational force.

Step 2. Explanation for option (a)

The baseball moves in the projectile motion all the time. The acceleration in the projectile motion is always acted in the downward direction, and it is constant. It is never zero.

Hence, option (a) is incorrect.

Step 3. Explanation for option (c)

At the highest point in the projectile motion, the vertical component of the velocity is zero. The resultant of the magnitude of the velocity is the slowest.

Therefore, the correct option is (c).

Step 4. Explanation for option (d)

Option (d) is not correct because more than one of the above is not true. Only option (c) is true.

Hence, option (d) is an incorrect answer.

Step 5. Explanation for option (e)

Option (e) is wrong because one of the above options is true.

Hence, option (e) is not correct.