Name: Date:
Power
Part 1: Concepts:
1. Take a sampling of a few of the objects that are used on a daily basis and complete the chart
given below
Part 2: Practice Problems: mg @dlfa (Mg; ; /{3 9:
' 2. A basement light has a power of 75 W. How mu
Electric Currents
Current
A moving charge creates an electric
current.
Electric current is the amount of charge
that moves through the cross-sectional
area of a wire per unit interval of time.
I
q
t
Unit: Ampere, Amp (A)
Electric Currents
In a conducto
Power,
E.M.F.,
and
Internal Resistance
Power
Power is defined as the rate at which
energy is used by or supplied to the circuit.
Power is dissipated in resistors (as heat)
P
W qV
W
t
and
q It
W ItV
or
W
IV
t
P IV
V IR
P I 2R
P
V2
R
1
E.M.F.
(Electromot
Resistors in Series and in
Parallel
Series
Voltage drop is different across each
resistor
The total voltage drop across the circuit is
equal to the sum of the voltage drops
across the individual resistors
Current is the same through each resistor
Serie
Relative Motion
Relative Motion
All motion, and even time, is relative to an
observer.
A person that is walking forward at 4km/h on a
ship will be seen as moving faster by an observer
on the shore.
This occurs because the speed of the ship is
added to