Recent content by Felicity26

Oh, I see what you're talking about. It's that Ff=Mu(Fn) and W=F(d). So then I find the friction force and then use that to calculate the distance. I see.

Alright, I get that. But can you elaborate a little more about the dry friction equation, because I really have no clue what that is. So far, I've only been taught at school about the Ek=1/2mv^2 equation anda couple of really basic ones. Thanks :)

So h actually doesn't matter?

I don't think I can use sqrt(2gh) for the second part because the mass is at the bottom of the hill and the height is zero, so that would make the entire thing zero. Should I assume that the deacceleration is constant? Because if that's the case, then I can use v2^2=v1^2+2ad.

Homework Statement The top of a hill is height h, m above the ground. If there is a friction patch on the flat ground only and no friction on the hill, what will the speed of a box of mass m at the bottom of the hill? How long must the friction patch be to make the box's speed 1/3 of what it...

Thank you!

When I say the missing 1/2, I mean when you put then numbers into solve.

Sorry, I didn't refresh the page when I submitted the reply. I think I get it now. But, I was wondering, if the equation is 1/2mv^2, why is the half missing? (Oh, I was trying to look up the notation for potential energy and I got U and s as the sub for the spring, but I'm guessing I looked up...

I thought there was some kind of relation between height and distance. Right now, all I have is Us=1/2 mv^2, which would be 1/2 (25)(x)^2. Since I'm trying to find x, I'd have to find Us first. But I also have a kinetic energy of 800 J. So I'm guessing I'll have to find an equation that would...

Sorry, I don't know if the answer is 17.9m; I wasn't given an answer key. I put the numbers in and got 800 J. I was wondering if the equation Eg=mgh would be any help to figuring out the distance?

1. The energy from elastic potential is 1/2 kx^2. K is a spring constant and x is the displacement distance of the spring from its equilibrium position. How far will a spring of spring constant k=25 N/m compress if an obejct of mass 4 kg has an initial velocity of 20 m/s runs into the spring...