An automobile starter motor has an equivalent resistance of 0.0500ω and is supplied by a 12.0-v battery with a 0.0100-ω internal resistance.

(a) what is the current to the motor?
(b) what voltage is applied to it?
(c) what power is supplied to the motor?
(d) repeat these calculations for when the battery connections are corroded and add 0.0900ω to the circuit. (significant problems are caused by even small amounts of unwanted resistance in low-voltage, high-current applications.)

Answer

given,

resistance = 0.05 Ω

internal resistance of battery = 0.01 Ω

electromotive force = 12 V

a) ohm's law

        V = IR

     and volage

now,

inserting the values

      I = 200 A

b) Voltage

   V = I R

   V = 200 x 0.05

   V = 10 V

c) Power

    P = I V

    P = 200 x 10 = 2000 W

d) total resistance = 0.05 + 0.09 = 0.14 Ω

     I = 80 A

     V = 80 x 0.05 = 4 V

     P = 4 x 80 = 320 W

gas and liquid

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.