# Recent content by gamer_x_

1. ### Use the properties of logarithma to xpand the logarithmic function

I just realized I was stupidly thinking of x^2-1 not x^2+1. You can't really factor that term unless you go into imaginary numbers.
2. ### Use the properties of logarithma to xpand the logarithmic function

the first step makes sense: ln[(x^2+1)(x-1)]=ln(x^2+1)+ln(x-1) but then you continued: ln(x^2+1)=ln(x^2)+ln(1) You can't do that, but you can do something else to the x^2+1...
3. ### (simple)Journal Papers using Step Potential

Do you mean you need to reproduce the theoretical calculations present which involve a step function? I'm not exactly clear on what you're trying to do.
4. ### Boyle's Law [mmHg]

This is a really cool question. I was stumped for a few minutes before I started thinking about what additional effects are present when the capillary tube is vertical that were not there before. Do you remember in which direction pressure acts?
5. ### Rotation rate of hour hand on clock?

one of the key differences in your choices are the numbers 12 and 24. What do they represent, and which one is relevant in the case of a full rotation of the hour hand?
6. ### Heat equation with radiation effect

Yes, that is what I meant, except that I used the second derivative of temperature. I know there's a major difference, is your first derivative just a typo or is there something I missed? By assuming that T(x) << T(outer) I can get a temperature of approximately 175K. Thanks for all of your...
7. ### Heat equation with radiation effect

Perhaps I'm not approaching the problem the same way you are: \alpha = \kappa / c_p \rho C = \epsilon \sigma A * T(outer)^4 / (m*c_p) --> this is the delta T as contributed from external radiation, adjusted for the mass (which will have the inner and outer diameters in the...
8. ### Heat equation with radiation effect

you're right, there should be a constant in front of the second derivative of temperature wrt x: \alpha d^2 T(x)/dx^2 = C - \epsilon \sigma A*T(x)^4 However, I'm changing the problem into a 1D heat conduction problem because I want to solve the simpler version first. In...
9. ### Heat equation with radiation effect

Homework Statement Let's say you have a 3m long copper pipe, 3mm in thickness with a diameter of 170mm. You fix one end at 1K and insulate it to prevent conduction or convection between the air and the pipe itself. There is still radiation. Assume that the inside of the pipe has no effect...
10. ### Viscous Flow and Pressure Coefficient

in which dimension is flow?
11. ### Pulley on an incline

I don't understand where you're getting your angles from, unless one of the masses is also on a ramp? Can you describe the geometry of the setup a little better?
12. ### Calulating range

three hints: -in which axis is "range" measured? -what forces do you have acting in this axis? -based on these forces, formulate your acceleration and displacement equations.
13. ### Physics: skier problem

delta PE is just your change in gravitational potential energy, delta KE is your change in kinetic energy. Does this formula seem different than the one you used?
14. ### Simple Physics Problem - Acceleration Formula

x is final position, x_0 is initial position, v_0 is initial velocity, t is time, a = acceleration.
15. ### Absolute Error of a Given Function

double check all of your derivatives, and then yes, the next steps are plug and play.