Derive the equation for electrical conductivity in conductors using free electron theory?

wire in brush may conduct electricity from cell to drill and vice versa electrc shock possible

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.

the displacement produced by the body.  

the amount of force subjected to the body.  

the angle between the direction of force and displacement

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27