# Straight Line Kinematics Problem

1. Oct 12, 2015

### cvc121

1. The problem statement, all variables and given/known data

A baseball pitcher throws a ball at a speed of 47m/s. When the catcher receives the ball, he pulls his hand back through a distance of 0.035m in the process of making the catch. What was the acceleration of the ball as it was being caught, assuming the acceleration was constant. What was the acceleration of the ball as it was being caught?, assuming the acceleration was constant.

2. Relevant equations

3. The attempt at a solution

472 = 02 + 2(a)(0.035)
a = 472 / (2)(0.035)
a = 31557 m/s2

*I think my answer is totally unrealistic. I am not sure how to deal with the hand being pulled back 0.035m in the process of making the catch. Do I also need to calculate the distance travelled before making the catch?

Thanks! All help is very much appreciated!

2. Oct 12, 2015

### billy_joule

You answer is correct. What makes you think it isn't? The balls going around 170 km/hr, To stop in just 35 mm takes tremendous acceleration.

There's no way to do that. You don't have enough information.

3. Oct 12, 2015

### haruspex

To assess how realistic it is, determine the force. I gather a baseball has a mass of around 0.15kg. Compare the force with the weight of something.