Finding final Velocity given mass, force, and displacement

[Bearbull24.5]

Homework Statement

2.78 kg block is pulled (from rest) by a force (horizontal surface) of 15.8 N. The coefficient of kinetic friction is .106. What is the velocity after 2.88 m?

Homework Equations

fk=N(uk)
Vf=sqrt((2*W)/m

The Attempt at a Solution

I attempted to find the final velocity by first finding the work (w=Fx*deltax) and then plugging it into the Vf equation I have listed.

 

[tiny-tim]

Hi Bearbull24.5!

(have a mu: µ and a square-root: √ and a delta: ∆ )

fk=N(uk)
Vf=sqrt((2*W)/m
…
I attempted to find the final velocity by first finding the work (w=Fx*deltax) and then plugging it into the Vf equation I have listed.

That should be ok (assuming that m is inside the bracket).

What figures did you get?

 

[Bearbull24.5]

I got 5.7 for the final velocity and a work of 45.504 N m

 

[Bearbull24.5]

Do I need to use the coefficient of kinetic friction for anything?

 

[tiny-tim]

I got … work of 45.504 N m

No, you need to use the net force.