You have a grindstone (a disk) that is 98.0 kg, has a 0.335-m radius, and is turning at 100 rpm, and you press a steel axe against it with a radial force of 23.6 N. Assuming the kinetic coefficient of friction between steel and stone is 0.192, calculate the angular acceleration of the grindstone.

Give an example in which the electrical energy changes to light energy

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?

Point charges q1=+2.00μc and q2=−2.00μc are placed at adjacent corners of a square for which the length of each side is 1.50 cm . point a is at the center of the square, and point b is at the empty corner closest to q2. take the electric potential to be zero at a distance far from both charges. part a what is the electric potential at point a due to q1 and q2? express your answer with the appropriate units.