A baseball pitcher throws a baseball with a speed of 43 m/s. Estimate the average acceleration of the ball during the throwing motion. In throwing the baseball, the pitcher accelerates it through a displacement of about 3.5 m, from behind the body to the point where it is released (Fig. 2-37).

Never mind, I took a second look at it and everything came together :)

Hi mafiadx83, thanks for the question. The scenario in this problem is that a pitcher is throwing a baseball. In that scenario, the ball begins at rest in the pitcher's hand, and then they throw their arm forward to throw the ball. The problem says to assume that their throwing action takes place over a distance of $3.5 \textrm{ m}$. The final velocity of the ball is whatever velocity with which it leaves their hand at the end of the pitching action, and the problem tells us this is $43 \textrm{ m/s}$. That's how we make our assumptions, and the videos explains how to get the acceleration given the information provided, but please let me know if it isn't clear.

All the best,
Mr. Dychko

Hi kingrhino, thanks for the question. Writing $2.6 \times 10^2 \textrm{ m/s}^2$ is the safer way to write the answer if you were, for example, concerned that someone marking a test paper was looking closely at significant figures. Strictly speaking $260 \textrm{ m/s}^2$ also has only two significant figures, and the trailing zero does not count as a significant figure in this case. The trailing zero serves as a "place holder" in order to position the "2" in the hundreds place, and the "6" in the tens place. I've seen $260.$ with a barely visible "dot" following the zero to indicate three significant figures, but that's not a good idea, so don't do that since it's too difficult to see. When in doubt, use scientific notation as you suggested, but know that you can write answers with "place holder" zeros as well.

Best wishes,
Mr. Dychko