# Search results

1. ### Better Thermal Insulator for Glass - Neoprene or Silicone?

I am looking to improve the thermal insulation on one of my favorite glass mugs. I am choosing between a silicone glove or a neoprene wrap. What is the difference between a silicone baking mat and silicone rubber? Does silicone or neoprene have better thermal insulation?
2. ### Does an Induction Cooking Pan Need to be Completely Ferrous?

Do you think that a ferrous plate at the bottom would suffice though? Or would a completely ferrous pan be significantly better?
3. ### Does an Induction Cooking Pan Need to be Completely Ferrous?

I ask, "Does a ferrous pan for Induction Cooking need to be Completely Ferrous?" In other words, could just the bottom of the pan be a ferrous material for good inductive heat induction? Could I have a ferrous bottom, and ferrous sides that turn to a non-ferrous material after a couple...
4. ### Question on Surface Integral and Flux

Could I use, (3,-1,0)x(0,0,-1)?
5. ### Question on Surface Integral and Flux

Alright, so the corss product of two vectors will give me a vector that is perpendicular to the plane (which is in the direction that I want). I'm not sure what these vectors would be? How do I know what vectors to cross?
6. ### Question on Surface Integral and Flux

Would I compare triangles in the xy-plane?
7. ### Question on Surface Integral and Flux

Homework Statement I have a coordinate system, (x,y,z). There is a uniform-magnetic-field of 2.0 T that exists along the direction of the y-axis. There is a rectangular plane bounded by the points (3,0,0),(0,1,0),(0,1,1),(3,0,1). Calculate how much flux is traveling through the rectangular...
8. ### Finding Omega and Zeta from a Magnitude and Phase Plot

Yes, I am assuming that the AFM cantilever is being modeled as a second order system. With the cantilever tune, the phase curve is set to 90° of the resonant frequency. So would I be close enough in estimating that the natural frequency is 72.7 kHz?
9. ### Finding Omega and Zeta from a Magnitude and Phase Plot

I was able to calculate the value for the damping ratio; but I am having trouble finding the value of the natural frequency. Any ideas on how to solve for the natural frequency?
10. ### Finding Omega and Zeta from a Magnitude and Phase Plot

Could you elaborate? Where does this -3dB bandwidth come from? Is Q inversely related to the damping ratio, ζ? Thanks for your help.
11. ### Finding Omega and Zeta from a Magnitude and Phase Plot

Homework Statement I've been asked to estimate ωn and ζ from the magnitude and phase plot of an atomic force microscope. The magnitude and phase plot is attached. Does anyone know how to solve for these values?
12. ### Calculating Transformer Input Voltage?

The load is 1.5Ω, and Xm is also in Ω.
13. ### Calculating Transformer Input Voltage?

Homework Statement A 2400/240-V, 60-Hz transformer has the following parameters in the equivalent circuit of Figure 6.5: the high-side leakage impedance is (1.2+j2.0)Ω, the low-side leakage impedance is (0.012+j.02)Ω, and Xm at the high-side is 1800 . Neglect Rhe. Calculate the input voltage...
14. ### Electric Potential Question

Homework Statement Which of the following statements about the electric potential inside a metal object are correct? Check all that apply. The potential at any point inside a metal at equilibrium is equal to the potential at the surface, which may be nonzero. The potential is the same...
15. ### Which of the following

Which of the following.... Homework Statement In a collision between an electron and a hydrogen atom, it is useful to select both objects as the system because: A. The total momentum of the system does not change during the collision B. The forces the objects exert on each other are...
16. ### Finding Kinetic Energy of a Collision

Homework Statement A 900 kg car moving east at 31 m/s runs head-on into a 2800 kg truck moving west at 15 m/s. The vehicles stick together. Use the concept of the center-of-momentum frame to determine how much kinetic energy is lost. Homework Equations Kf= Ki(car) + Ki(truck) K=...
17. ### Rotational Velocity Problem

That's not the equation? Then what equation would I use to represent the rod with moment of inertia?
18. ### Rotational Velocity Problem

Moment of Inertia= mr^2. Sorry.
19. ### Rotational Velocity Problem

Homework Statement A thin uniform-density rod whose mass is 3.8 kg and whose length is 3.0 m rotates around an axis perpendicular to the rod, with angular speed 34 radians/s. Its center moves with a speed of 10 m/s. (a) What is its rotational kinetic energy? (b) What is its total kinetic...
20. ### Vertical Spring Potential Energy?

Homework Statement Say I have a vertical spring, with a mass attached to the bottom of the spring, and the spring is attached to the ceiling. Say I push up on the mass compressing the spring, and then I release the spring from rest. Do I need to take into account the gravitational...
21. ### Fun theory physics question

Hi, I was wondering this question: Why does U=mgh and U=Gm1m/R come out to similar values even when their equations are completely different? Thanks
22. ### Classic Football Kick Problem

You could square both sides, and then we can work it out from there?
23. ### Classic Football Kick Problem

Are there any sin and cosine laws that would help, like the square of sin added to the square of cosine equalling one?
24. ### Classic Football Kick Problem

hmm. what did you come out with?
25. ### Classic Football Kick Problem

Ok i'll, as well.
26. ### Classic Football Kick Problem

I dont see what you're getting at. I know there are these two equations, I need to solve a variable deltat to get one variable left. After I try to do that step, I get a ridiculous equation that I need to solve for theta. Is there any other process of doing this problem?
27. ### Classic Football Kick Problem

I attempted to solve for deltat, but when I plugged delta t from the 2nd equation into the first equation i get a long equation with costheta- costhetasintheta. I'm confused
28. ### Classic Football Kick Problem

the higher angle would be when the ball strikes the top of the post.
29. ### Classic Football Kick Problem

Because the problem does not supply deltat, where should that number come from? 54m/27m/s= 2s?
30. ### Classic Football Kick Problem

my answers dont seem to be working. I get for the largest angle possible: 54= 27^2sin(theta)^2/ (9.8) = .8520=sintheta= 58 degrees. would that be correct for the larger angle?