Basic one dimensional kinematics problem, need conceptual help

[OneTimePad]

Hello all,

I just came across a problem that I had previously solved. A relatively simple one. What I do not understand though is why I can use the equation that I have used so many times in this particular situation. Here it is:

Homework Statement

A baseball pitcher throws a baseball with a speed of 41 m/s. Estimate the average acceleration of the ball during the throwing motion. In throwing the baseball, the pitcher accelerates the ball through a displacement of about 3.5 m, from behind the body to the point where it is released.

V₀ = 0 m/s
V_f = 41 m/s
d (X_f - X_i) = 3.5m

Homework Equations

Equation for motion at constant acceleration:
( V_f² - V₀² ) / 2d = a

The Attempt at a Solution

41² / (2*3.5) = 240.14 m/s²


My question is: Why can I use this equation in the first place? Aren't these equations only valid if the acceleration is constant? Where in the problem does it suggest that the 'average acceleration of the ball during the throwing motion' is indeed constant?

Any insights would be greatly appreciated.

Thanks in advance.

 

[I like Serena]

It says in the question: "Estimate the average acceleration of the ball during the throwing motion."

So you use formulas that would work if the acceleration were constant.
The result would "estimate" the actual average acceleration.

 

[OneTimePad]

Oh, I see now. Thanks