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Impulse question

1. The problem statement, all variables and given/known data
Calculate the impulse(change in momentum) in each of the following situations.
Also, state the direction of the change in momentum.
A 4kg ball strikes a stationary pin head-on at a speed of 3m/s. It continues to move in its original direction, but its speed is reduced to 2m/s.
2. Relevant equations
p=mv

3. The attempt at a solution
I have a test the next day & we might have some questions on impulse but the thing is that our teacher never really spent time on it for some odd reason. But yeah, just in case he might troll us & put some impulse questions I might as well do some. So all I got so far is:
p1=mv1
p1=3x4
p1=12
==========================
p2=mv2
p2=4x2
p2=8
==============================
(delta)p=p2-p1
=8-12
(delta)p=4
===================
not sure what to do next after..
 

NascentOxygen

Mentor
9,172
1,028
You calculated Δp = -4
It needs units.

You could say it has delivered an impulse of 4 ... to the pin in the direction of motion of the ball, so its own momentum has reduced by that amount in the direction of its original motion.
 

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