- #1

TheRhinoMan

**Did I do this problem right? I didn't use some of the info...**

Oh well... if it doesn't, it's moveable. :)

Hello Ladies and Gents,

I'm new on here, and I was wondering if someone could help me with my physics HW; And forgive me if I don't get it right away. :)

Here's the problem...

A 40kg. wagon is towed up a hill inclined at 18.5(degrees) with respect to the horizontal. The tow rope is parallel to the incline and has a tension of 140N in it. Assume that the wagon starts from rest at the botton of the hill and neglect friction. How fast is the wagon going after moving 80m. up the hill?

I tried doing this one, and well...

m=40kg.

delta(x)=80m.

Angle=18.5

Force(net)=140N

vf=?

Just stating the known, and then I...

v(fin)^2=v(ini)^2 + 2a(delta)x

vf^2 = 0 +160a

F(net)=ma

140=40a

a=3.5

in which case...

vf^2= 160(3.5)

vf^2= 560

vf = 23.66

So, that's what I did; I'm sure it's wrong, just because I didn't use the angle.

So... that's my question... what did I do wrong? Or did I do it right?

Thanks a bundle!

P.S. Heheh, I have a whole lot of physics "?"s that I don't understand...

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