i dont understand wat im doing wrong here is my problem(adsbygoogle = window.adsbygoogle || []).push({});

Choose the positive direction to be

from the pitcher to the plate (some answers

may be negative).

A pitcher throws a 0.13 kg baseball so that

it crosses home plate horizontally with a speed

of 31 m/s. It is hit straight back at the pitcher

with a final speed of 28 m/s.

What is the impulse delivered to the ball?

Answer in units of kg m/s

Find the average force exerted by the bat on

the ball if the two are in contact for 0.0011 s.

Answer in units of N

ok here is my work

Impulse=m(vf-vi)

.13(28-31)=-.39

then for average force i have

I=t*af

-.39=.0011*af

af=-354.5454545

but i change my signs to positive right?? either way my answer is wrong help please

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# Homework Help: Impulse and average force of baseball

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