# Search results

1. ### When can one Change order of derivatives?

Here is an example... d/dz(dp/dx) = d/dx(dp/dz) I dont remember learning this in my calculus or differential equations classes unless it was called something else.
2. ### Weight before/after change in rotation Speed

Homework Statement How would the weight of a person in some place (48 North and 123 West) change if the rotation rate increased so a day was 3 hours long? Homework Equations F=ma The Attempt at a Solution The above is not the only equation I think that is needed for this. Not...
3. ### Finding volume of swimming pool

Homework Statement A swimming pool is circular with a 40-ft. diameter. The depth is constant along east-west lines and increases linearly from 2 ft.at the south end to 7 ft. at the north end. Find the volume of water in the pool. Homework Equations Dont know how to enter integrals...
4. ### Double Integrals Limits of Integration

I am just starting to do double integrals and came acorss an issue. I remembered from single integrals when we integrate from limits for say -1 to 1, we can double it and change integration limits to 0 to 1. Now, when is this the case? Basically, when can we not do this?
5. ### Rearranging an equation

1. Homework Statement This is a science equation, just having trouble rearranging to solve for a variable. The equation is below. Basically I want the equation to be in the form of delta T = T2-T1 = ... 2. Homework Equations (-R/L)[ln(p2/p1)] = [(1/T2)-(1/T1)] 3. The...
6. ### Finding a relationship using 1st Law of Thermodynamics

1. Homework Statement Derive a relationship between dq/T , dT/T, dp/p , Cp , and R for an ideal gas. 2. Homework Equations dQ = dU + dW and/or dq = du + dw (for a unit mass) p*d(alpha) = dw (alpha = specific volume V/m) du = Cv*dT p(alpha) = RT (Ideal gas equation, a different...
7. ### Molar Specific Heat

1. Homework Statement What si the difference between the molar specific heat at constant volume and at constant pressure? Homework Equations The Attempt at a Solution
8. ### Gravity Ratio

1. Homework Statement : The center of a 1.00 km diameter spherical pocket of oil is 1.20 km beneath the Earth's surface. Estimate by what percentage g directly above the pocket of oil would differ from the expected value of g for a uniform Earth? Assume the density of oil is 8.0*10^2 (kg/m^3)...
9. ### Gravity Problem

1. Homework Statement : It can be shown that for a uniform sphere the force of gravity at a point inside the sphere depends only on the mass closer to the center than that point. The net force of gravity due to points outside the radius of the point cancels. Question: How far would you have...
10. ### Current Carry Wire With A Loop

1. Homework Statement : A. Determine the magnetic flux through a square loop of side a (see the figure) if one side is parallel to, and a distance b from, a straight wire that carries a current I. Express your answer in terms of the variables I, a, b, and appropriate constants. Answer...
11. ### Shrinking Loop

1. Homework Statement : A circular loop of flexible iron wire has an initial circumference of 166cm , but its circumference is decreasing at a constant rate of 13.0cm/s due to a tangential pull on the wire. The loop is in a constant uniform magnetic field of magnitude 1.00 T, which is oriented...
12. ### Magnetism (Current-Carrying Wires)

1. Homework Statement Two straight wires, each with a resistance of 0.170 ohm and a length of 3.90m, are lying parallel to each other on a smooth horizontal table. Their ends are connected by identical, non-conducting, light springs, each spring having an unstretched length of 1.08 cm. A wire...
13. ### Find the x-component of the magnetic force on the wire

1. Homework Statement : A wire with a length of 29.0 cm lies along the z-axis and carries a current of 9.00 A in the +z-direction. The magnetic field is uniform and has components Bx = -0.204T, By = -0.968T, and Bz = -0.328 T Homework Equations 1. Find the x-component of the magnetic...
14. ### What is the charge on the second sphere?

1. Homework Statement Two small plastic spheres are given positive electrical charges. When they are a distance of 14.2cm apart, the repulsive force between them has a magnitude of 0.220 N. A. What is the charge on each sphere if the two charges are equal? Ans: 7.02X10^-7 B. What is the...
15. ### Strategy to solve Mechanics!

Homework Statement I don't have a specific problem. I have an exam coming up. Our class was all about Mechanics. So I want to have a strategy to solve problems, that I can follow. Can someone help me? Topics include: Kinematic Problems (Motion in 1-3 Dimensions) Forces Conservation...
16. ### Potential Energy of Spring

1. Homework Statement The force exerted by an unusual spring when it's compressed a distance 20cm from equilibrium is given by F= -kx-cx3, where k= 233 N/m and c= 4.0kN/m3 Question: Find the energy stored in this spring when it's been compressed 20cm. 2. Homework Equations...
17. ### Work/Kinetic Energy

1. Homework Statement A ball of mass 0.805 kg is tied to the end of a string of length 1.61 m and swung in a vertical circle. Question 1: During one complete circle, starting anywhere, calculate the total work done on the ball by the tension in the string. Ans: 0J Question 2: During...
18. ### Tether ball problem (Forces)

1. Homework Statement A tether ball leans against the post to which it is attached. The string is attached to the ball such that a line along the string passes through the center of the ball. The string to which the ball is attached has length 1.50 m and the ball's radius is 0.108 m and has...