State what is meant by the centre of mass of an object

What is the most useful equation for electric power?

What are atoms of the same element with varying number of neutrons

1. a camcorder has a power rating of 19 watts. if the output voltage from its battery is 7 volts, what current does it use?answer units 2. a 1.5m wire carries a 6 a current when a potential difference of 57 v is applied. what is the resistance of the wire? your