What is the potential energy, if a
body of mass 250 kg is at a height of 30
metre? ​

Which statement correctly describes a step-up transformer? a. it increases the amount of electric energy available. b. it increases the voltage of an electric current. c. it changes direct current into alternating current. d. it has more loops of wire in its primary coil.

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.

How many excess electrons must be present on each sphere if the magnitude of the force of repulsion between them is 4.57×10−21 newtons?