A spherical snowball is melting in such a manner that its radius is changing at a constant rate, decreasing from 25 cm to 16 cm in 30 minutes. At what rate, in cm3 per minute, is the volume of the snowball changing at the instant the radius is 9 cm?

The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a magnitude of 7.0 × 10-6 c/m2. (a) what is the magnitude of the electric field within the cell membrane? (b) find the magnitude of the electric force that would be exerted on a potassium ion (k+; charge = +e) placed inside the membrane.

If you place a magnet under a clear dish, and sprinkle iron fillings over it, above what part of the magnet will most of the fillings gather

Current from a charged capacitor lights a bulb. as time goes on the brightness of the