Two point charges, initially 10 cm apart, are moved to a distance of 20 cm apart. By what factor does the resulting electric force between them change?

Agas contained within a piston-cylinder assembly undergoes three processes in series: process 12: compression with pv= constant from 1 bar and 1 liter to 4 bar. process 23: constant pressure expansion to 1 liter. process 31: constant volume calculate the pressure and volume at each state, and sketch the processes on a p-vdiagram labeled with pressure and volume values at each numbered stat

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island

What is the weight of a 8-kg substance in n, kn, kg·m/s2, kgf, lbm·ft/s2, and lbf?