Recent content by mindcircus

This is a physics problem, but I have some trouble finishing it up. I evaluated an integral, which gave me inv tan of (1-E)tan(theta/2)/(sqrt (1-E^2) evaluated from 0 to 2pi. I changed the limits to 0 to pi, and multipied by 2, because tan x doesn't exist at 2pi. I know that if you...

A disk of radius R rolls without slipping inside the parabola y=a*x^2. Find the equation of constraint. Express the condition that allows the disk to roll so that it contacts the parabola at one and only one point, independent of position. I know the equation of constraint: On the disk...

Consider a simple harmonic oscillator. Calculate the time averages of the kinetic and potential energies over one cycle, and show that these quantities are equal. Next, calculate the space averages of the kinetic and potential energies. I'm completely confused about these terms. Time...

Yes, sorry, that's what I meant. And that's what I'm trying to do, I wasn't typing carefully. I have to integrate v to get r.

If the velocity and force are perpendicular, it's centripetal motion. But I don't really know what to do with that. I know velocity is the cross product of the radius and omega (d.theta/dt). Because I'm trying to find the radius, I can't use this, I think? Otherwise, when I try to do the...

The motion of a charged particle in an electromagnetic field can be obtained from the Lorentz equation for the force on a particle in such a field. If the electric field vector is E and the magnetic field vector is B, the force on a particle of mass m that carries a charge q and has a velocity...

Right, water is more dense as a liquid than as a solid, so the solid-liquid boundary line in the phase diagram for water has a slightly negative slope, as opposed to the usual positive slope for other substances. Therefore, for water, the increase in pressure at constant temperature would favor...

A train moves along the tracks at a constant speed u. A woman on the train throws a ball of mass m straight ahead with a speed v with repsect to herself. What is the kinetic energey gain of the ball as measured by a person on the train? By a person standing by the railroad track? How much...

A boat with initial speed v is launched on a lake. The boat is slowed by the water by a force, F=-ke^(bv). Find the expression for speed v(t). I've done the problem, but my answer seems too odd to be right...it may be my calculus. I've drawn a FBD, with the normal force and weight...

Any help would be MUCH appreciated! Vector A=yi+zj+xk Surface S is defined by z=1-x^2-y^2 where z is greater or equal to 0. Find the value of the surface integral of (grad x A)*dA (The “x” is the cross product.) I know this uses Stoke’s Theorem: line integral of the closed curve of...