1.3 Electricity in the home + Calc

• Natuurkunde
• Middelbare school
• vwo
• Leerjaar 3

Hello 3 TVS!

a little exercize to warm up!

Quantity	Abbreviation for Quantity	Unit	Abbreviation for Unit
Distance	s	Meter	m
Power	?	?	?
Voltage	?	?	?
Current	?	?	?

a little exercize to warm up!

Quantity	Abbreviation for Quantity	Unit	Abbreviation for Unit
Distance	s	Meters	m
Power	P	Watt	W
Voltage	U (Unterschied)	Volt	V
Current	I (for Intensité)	Ampère	A

Today

- Some theory

- Question form using a cool application!

- Discussing our findings 

- Summary

- Time for homework

Some theory

Remember Power(in Watts)?

The power of a battery is the amount of energy it puts out per second.

E = P x t,   so P = E/t

How does this connect to electrical circuitry? 

Power is relative to the Current and Voltage of electricity

If the voltage is higher, the amount of energy used up per second is ???

If the current is stronger, the amount of energy used up per second is ???

The relationship between power, voltage and current is....

P = U x I

Example question

If a battery has the Power to put out 3 W per second,

How much Energy did it put out if you run it for 3 minutes?

How do you solve a question like this?

What do we know?                P = 3 W           t = 3 m = 180 s

What do we need?                E  = .........

E = P x t                                     E = 3 x 180 = 540 J

Example

If a battery has a power output of 5 W and the circuit has voltage of 2 V. Calculate the Current running through the circuit.

What do we know?                       P = 5 W        U = 2 V

What do we need?                       I = ...............

P = U x I                                            5 = 2  x  I                I = 5 : 2 = 2,5 A

The total Power used in a system can be calculated!

;l

If a camera needs three batteries that output 22.5 Watts. 

What is the total Power that is needed for the camera to work?

22.5 + 22.5 + 22.5 = 67.5 Watts

Question form

s

Afterwards, make your homework 1 through 9  for 1.3

but not 2bc, 3, 7c and 8

Discussing the answers you've found

Part one

T F T F F

Part two(1)

It could be yes because all electronics in your house are in parallel so everything is running on 230 Volts.

It could be no because lightbulbs and electronics have different resistances. The amount of electricity running and powering a washing machine, is not the same as the electricity running a television, and this also counts for different types of lamps.

Part two(2)

Stays the same

Lower

Higher Voltage/More batteries

Summary time...

Homework time!

make your homework 1 through 9 for 1.3

but not 2bc, 3, 7c and 8