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?

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...
3. 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...
4. 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?
5. 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...
6. 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...
7. 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...
8. 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=...
9. 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...
10. 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...
11. 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
12. Classic Football Kick Problem

Homework Statement A football kicker can give the ball an initial speed of 27 m/s. He is 54 m from the goalpost which has a crossbar 3.37 m high. (a) What is the largest angle of elevation that he can kick the football and score a field goal? (b) What is the smaller angle of elevation that...
13. Position of an object after a certain amount of time?

Homework Statement Your location is at the origin. When an object passes you, it is traveling 5 m/s in the −z direction. If the object's mass is 200 kg, and the net force on the object remains constant at ‹ 0, 0, −30 › N, what is the position of the object 20 seconds after it passes you...
14. How to Change a Horizontal Vector to Move in a 45 degree angle

Homework Statement I am using vPython, and object moves in a +x direction with a vector of <1e7,0,0>m. I need to now change the vector so that it now moves in the same +x direction, but also moving in the northeast direction at an angle of 45 degrees. The Attempt at a Solution I...
15. Basic Concept Physics Question

Homework Statement An object is moving in the +z direction. Which, if any, of the following statements do you know must be false? Check all that apply. 1. velocity of z is zero. 2. The net force on the object is in the -z direction. 3. The net force on the object is zero. 4. The net...
16. INtegral Problem

Homework Statement Integral of (sec(10x)^2)*(tan(10x)^6)dx Homework Equations The Attempt at a Solution The powers are throwing me off a little bit. I realize that the derivative of tan is sec^2, bt how will that help me with this problem?
17. Double Integral Problem Help

Homework Statement ∫4to5 ∫1to2 (1x + y)−2 dy dx The Attempt at a Solution I am confused about what to do with this negative 2. Any ideas?
18. Tangent Plane Problem- Simple Question

Homework Statement Consider the function f(x,y) = 4-x^2+3y^2 + y. Let S be the surface described by the equation z= f(x,y) where f(x,y) is given above. Find an equation for the plane tangent to S at the point (-1,0,3) The Attempt at a Solution Ok, SO i solved for the gradient of F...
19. Velocity and Acceleration Vector Problem

Homework Statement Find the velocity and acceleration vectors for the following curves. Determine the points where the velocity vector is changing DIRECTION but not changing SPEED, and the points where the velocity vector is changing SPEED but not DIRECTION. For: a. f(t) = (t,t2,t3)...
20. Vector Tanget Problem

Homework Statement The function f(t)= (t2,1/t) represents a curve in the plane parametrically. Write an equation in parametric form for the tangent line to this curve at the point where t=2 The Attempt at a Solution I can solve the gradient from an implicit equation, but solving...
21. Applied Vector Problem

Homework Statement The equation T(x,y) = x2y-y2 + 180 is a temperature equation at point (x,y). If One is standing at point (3,1), what direction should he move in order to decrease the temperature? Secondly, if one moves a unit distance in this direction found above, how much should...
22. Multivariable Calc Image-Graph Problem

Multivariable Calc Image-Graph Problem!!!! Homework Statement Given a function f: R-R2 , by f(t) = (t, t^2 - cos(t)), which represents a curve in the xy plane parametrically, give a function whose GRAPH represents this same curve. 2) Also, give a function h whose level set for height k=0...
23. To Vector Problems Difficulty

Homework Statement Find the implicit form for the plane that contains the origin and the line: L(t) = <1+t,1-t,2t> The Attempt at a Solution' So, the point P = (1,1,0) and vector v= <1,-1,2>. To find the implicit equation for the plane using the form ax + by + cz = d , I will...
24. Tangent Plane Question

Homework Statement Find all the points on the surface x^2+y^2-z^2=-1 where the tangent plane is perpendicular to the vector <1,0,2>. I'm confused! The Attempt at a Solution So, the gradient would be: <2x,2y,-2z>, but what do I do with the gradient vector to find these points...

Homework Statement Write the vector <1,7> as a sum of two vectors, one parallel to <2,-1> and one perpendicular to <2,-1> Homework Equations DOt Product The Attempt at a Solution I'm confused on where to begin this problem. Should I be using the dot product? Thanks
26. FInding Points of Tangent Line w/ Vectors

Homework Statement Consider the ellipsoid 4x^2+2y^2+z^2 = 19. Find all the points where the tangent plane to this ellipsoid is parallel to the plane 2y−8x+z = 0. Homework Equations The Attempt at a Solution So I found the normal vector to the tangent, <8x,4y,2z>. I also...
27. Vector Tangent Line Problem

Homework Statement Let f(x,y) = 5y^(2)-(2x^(2)+xy) Then an implicit equation for the tangent plane to the graph of f at the point (0,-2) is Homework Equations The Attempt at a Solution I understand that I should take the derivative to find the gradient vector. For the...
28. Vector Plane Problem

Homework Statement The planes 3y-4x-4z = -18 and 3x-2y+3z = 14 are not parallel, so they must intersect along a line that is common to both of them. The vector parametric equation for this line is: L(t)= ? Homework Equations Cross Product Seems like it would be relevant here, but how...
29. Vector Tangent Line Problem

Homework Statement The parametric form for the tangent line to the graph of y = 2x^(2)+2x-1 at x = -1 is Homework Equations The Attempt at a Solution I am confused about where to begin this problem. Any thoughts? Thanks!
30. Quick and Easy Vector Problem Help

Homework Statement Consider the line L(t) = <1-3t,0>. Then: L is parallel, perpendicular or neither, to the Line L(t)= <6t-2,-3> Homework Equations The Attempt at a Solution I am stumped!