- #1

magma_saber

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## Homework Statement

A 70kg mass is in a space and moving at 2.5 m/s. You push it with 200N for 4 m. You then move to the front of the mass and push it backwards with 170N for 3 m.

What was the total work done?

What was the final velocity?

## Homework Equations

W = rest energy + F

_{1}*r - F

_{2}*r

## The Attempt at a Solution

rest energy = 1/2*70*(2.5)

^{2}= 218.75

F

_{1}*r = 200*4 = 800

F

_{2}*r = 170*3 = 510

W = 218.75 + 800 - 510 = 508.75 J

How would i get the final velocity?