Calculating Speed after Impulse of 6 Ns

[kerbyjonsonjr]

Homework Statement

A 2kg object is moving to the right with a speed of 4 m/s when it experiences an impulse of 6 Ns .

Homework Equations

mv+mv=mv

The Attempt at a Solution

Since the impulse is just the change in momentum I put in 2(4)+2v=6 so wouldn't v be -1?

 

[tiny-tim]

hi kerbyjonsonjr!

(btw, which direction is the impulse?)

Since the impulse is just the change in momentum …

yes that's correct

… I put in 2(4)+2v=6 so wouldn't v be -1?

what is 2(4)+2v=6 supposed to be? …

the impulse is the difference between the momentum after and before …

try again ​

 

[kerbyjonsonjr]

got it now! thanks for the help! I messed up. It should have been the final minus the initial. So it's 2v-2(4)=6 which gets me v= 7 m/s. Thanks for the help!