Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 times 107 n/c. what is the magnitude of the force on a calcium ion with charge +e? express your answer using two significant figures.

Diamond will scratch quartz. true or false

The radius of a sphere is increasing at a rate of 9 cm/ sec. find the radius of the sphere when the volume and the radius of the sphere are increasing at the same numerical rate.

Engines for propeller-driven aircraft are limited in their maximum rotational speed by the fact that the tip speed of the propeller must not approach the speed of sound in air (mach i). taking 6 ft as a typical diameter for a propeller of a light airplane and 1100 fils as the speed of sound, find the upper limit on the rpm (revolutions per minute) of the propeller shaft.