A planet, of mass 4. 0 x 1027 kg, is attracted by a second planet of mass 1. 5 x 1028 kg, when their centres are 7 x 1014 m apart. Calculate the value of the gravitational force between them.
An electron is released from rest in an electric field of magnitude 400 N/C.
(a) Determine the magnitude of the electric force on the electron.
(b) Determine the magnitude of the acceleration of the electron.