When a baseball is thrown straight upward, what is its acceleration at its greatest height?
a. 9.8 m/s2 upward b. 9.8 m/s2 downward (my answer? ) c. 0 m/s2 d. 9.8 m/s2 horizontally

When a baseball is thrown straight upward, its acceleration at its greatest height is equal to: c. 0

In Physics, the acceleration of an object or body is calculated by subtracting its initial velocity from the final velocity and dividing by the time.

Mathematically, acceleration is given by the formula;

Where:  

A baseball that is thrown thrown straight upward, experiences motion due to the acceleration of gravity.

Also, the final speed of an object is equal to zero (0) at the greatest height because it came to a stop while the initial velocity is equal to zero (0), since it would accelerate from rest.

Deductively, the rate of change of velocity with respect to time is equal to zero (0) and this is the value of baseball's acceleration.

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a = 0

Explanation:

When a baseball is thrown straight upward, it moves upward under the action of gravity. We know that at the highest point, the speed of the object is equal to 0. The rate of change of velocity is called acceleration of an object.

Since, the speed is 0 at the height point, so, its acceleration at its greatest height is 0. Hence, this is the required solution.