какой должна быть тангенциальная скорость Земли, чтобы человек на экваторе был невесомым

Which is not a source of noise pollution? a)airplanes b)acid rain c)machines d)cars

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.

Holes drilled several kilometers into earth’s crust provide direct evidence about earth’s interior in the form of