Velocity as a function of force/impulse/time.

1. Mar 2, 2008

the7joker7

1. The problem statement, all variables and given/known data

The force shown in the force vs time diagram in Figure P6.11 acts on a 1.5 kg object. Find the impulse of the force, the final velocity of the object if it is initially at rest, and the final velocity if initial velocity is -2.00 m/s.

http://books.google.com/books?id=wD...x_cOMU0&sig=cqAzhugYbnZdpBwdwDdlRM82s1g&hl=en

2. Relevant equations

V$$^{2}$$ = V$$_{0}$$$$^{2}$$ + 2a$$\Delta$$x

3. The attempt at a solution

I know impulse is just 8 newton seconds, and i know that's the right answer. But the 2nd question is getting me.

V$$^{2}$$ = 0 + 2(2/1.5)(5) gives V$$^{2}$$ = 13.33. so v = 3.65.

But the answer is v = 5.3.

Where did I go wrong?

2. Mar 2, 2008

Shooting Star

This is when accn is const, which here it's not.

Use impulse = change in momentum.

3. Mar 2, 2008

Staff: Mentor

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