Recent content by WahooMan

I know the integral to compute work done is (integral from a to b) F * dl where F and l are vectors, but I don't understand how I would use that in a problem. 1. Are a and b moments in time? 2. What is dl? Is that the same thing as l2-l1? So would it be (integral from a to b)...

Any help at all would be appreciated..

Homework Statement A 4.0 kg object moving in two dimensions initially has a velocity V1 = (11.0i + 20.0j)m/s. A net force F then acts on the object for 2.0s, after which the object's velocity is V2 = (16.0i + 32.0j)m/s. Determine the work done by F on the object. Enter your answers...

Homework Statement When 2.0g of NaOH were dissolved in 53.0g water in a caloremeter at 24.0 degrees Celsius, the temperature of the solution went up to 33.7 degrees Celsius. Homework Equations q = c * m * delta t -(c * m * delta t) = (c * m * delta t) c = specific heat, m =...

So what should I put? Thank you so much for your help I have class in 2 hours and I need to get this done.

Homework Statement Here is my lab: http://comp.uark.edu/~rallan/Exp20.pdf Homework Equations None that I know of The Attempt at a Solution I ran the experiment once on a known substance and once on an unknown substance. Here are my results: In the known substance, Pb Hg...

The equation that I have to find Impulse (J) is: J = (integral from Ti to Tf) F * dt I think dt means difference in time but I'm not sure. Can someone explain to me what dt is and how to calculate it?

What do you mean "the projection of the pendulum on the vertical line"? How do I find L?

Homework Statement A pendulum 2.00m long is released (from rest) at an angle (theta) = 30 degrees. Determine the speed of the 70.0g bob: (a) at the lowest point (theta = 0 degrees), and (b) at (theta) = 15 degrees. Homework Equations I really don't even know where to begin with this...

mv^2/r = mu(mg) m's cancel v^2/r = mu(g) 2.51^2/1.2 = mu(9.80) 5.26 = mu(9.80) mu = 0.54 Thank you so much for helping me

Homework Statement A block of mass 3.5kg rests on a rough horizontal turntable at a distance of 1.2m from the axis of rotation. If the block begins to slide when the turntable is rotating at 20.0 rev/min, what is the coefficient of static friction between the block and the turntable...

Wow.. I got it this time.. I hope I don't make such careless mistakes tomorrow on the test.. So I always use cosine when finding Fn? Would I ever use sine?

Sum of the forces = ma (39.2-16.3) = 22.9 = 8a a = 2.86 m/s^2 vf^2 = vi^2 + 2a(xf-xi) vf^2 = 0 + 2(2.86)(4) = 22.88 vf = 4.78 m/s I'm getting closer, but I need 5.4 m/s

Ok, I've got Fg = mg = (8)(-9.80) = -78.4N Fn = mgcos(theta) = 78.4cos30 = 67.9N Ff = mu(Fn) = 0.24(67.9N) = -16.3N Fa = mgsin(theta) = 78.4sin30 = 39.2N Sum of the forces = ma (39.2+67.9-78.4-16.3) = 12.4 = 8a a = 1.55 m/s^2 vf^2 = vi^2 + 2a(xf-xi) vf^2 = 0 + 2(1.55)(4) = 12.4...

Please help me, I have a lot of studying to do and I've been trying to figure this problem out for more than two hours now. I just need to know in what situations I use sine and when to use cosine, not just in this problem but in general.