# 4.7 Q

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A 0.15-kilogram baseball moving at 20 m/s is stopped by a catcher in 0.010 seconds. The average force stopping the ball is:

(A) 3.0x10^-2 N

(B) 3.0X10^0 N

(C) 3.0X10^1 N

(D) 3.0X10^2 N

The explanation says that it takes 0.010 seconds for the baseball to accelerate from 0 m/s to 20 m/s, but that doesn't really match up with the question... Is the wording a little weird?

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I think it says it takes 0.01 seconds for the baseball to accelerate from 20 m/s to 0 m/s, which exactly matches up with the question.  Delta-V is V_final - V_initial.

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