Recent content by jl1642

No, the textbook introduces the method with an example question, exactly as I wrote above, with 80 + (0.1*80).

Thanks! I thought I was right, it just messed me up that the textbook was wrong.

I have a relatively simple problem that I'm having trouble with. A ship is going at 0.90 c, over a distance of 80 light years. In my text the method for determining the time spent traveling is: 80 years + (0.1 * 80) = 88 years This method seems logical, at 0.9 of the speed of light this...

Thanks so much cepheid, I've been working on this for a while and couldn't get any headway. :-)

Okay, so if the net horizontal and vertical force is 0, this is what I have so far: \SigmaFx = 0 = \mu (mg - FAy) + FAx and FAx = W / d I think I have it now. Thanks!

It wasn't obvious in my course material, but thanks for the help.

As I said, the next question asks what angle the force is applied at, so I know it isn't horizontal. The answer I gave has already been marked, and the correct value for the angle of the force applied was 84.0 degrees.

Thanks! I didn't know that normal force was the net upward force. So mg - FAy = FN

Work only applies for the force applied in the direction of displacement, which is horizontal. It can't help me with the force applied vertically.

No, I know it is more complex than that. Thanks for the help though.

Oh! Do I subtract the y component of applied force from the normal force? Is that what is equal to Fg?

I thought that the normal force is exactly equal to the force of gravity, but in the opposite direction. I see what you mean though. If the force of friction is equal to the x component of FA then F cosθ = (mu) Fn But how do I get Fn then?

The following question asks the angle that the wagon is pulled, so the angle is not 0. I know there are horizontal and vertical components of the applied force, that is what I am trying to find out.

I want to solve for the force applied by the parent.

Sure; Parent is pulling wagon. The combined mass of the wagon and children is 50 kilograms. The adult does 2.2 x 10^3 Joules of work pulling the wagon 60 meters at a constant speed. The coefficient of friction between the two is 0.26. I've been working with : W = F*d*cos(Theta) If...