physics is electrifying

Question 1

What is the definition of energy? And what is the unit?

Answer 1

the ability to do work
unit: joule

Question 2

sort the 9 energies into 2 categories.

Answer 2

potential energy: gravitational potential (Ep), elastic potential (Eep), chemical potential (ECP), electrical (Ee), nuclear (En),

kinetic energy: kinetic energy (ek), heat (q), sound (es), light (Es)

Question 3

What is the law of conservation of energy?

Answer 3

energy can only be transformed or transferred, not created or destroyed, except in a nuclear reaction.

Question 4

What is transferred?

Answer 4

changed from one place to another.

Question 5

What is transformed?

Answer 5

changed from one type to another.

Question 6

eg. a person jumping on the trampoline

Answer 6

Initially, The trampoline has elastic potential energy (eep). This is transferred to the person as they jump into the air. The elastic potential energy is transformed into kinetic energy (ek), gravitational potential energy (ep), and heat (q).

Question 7

state the law of attraction

Answer 7

objects that are oppositely charged will feel an attractive force towards each other, but objects with the same charge will repel.

Question 8

what is a conductors and insulators? give examples.

Answer 8

Conductors are materials that have free e- and allow e- to flow through them.
eg. any metal + graphite

insulators are materials that do not have free e- and do not allow e- to flow through them
eg. plastic, rubber, wood, glass, air

Question 9

What is charge separation?

Answer 9

the imbalance of charges between the two locations.

Question 10

Name the 3 ways that charged objects can become neutral again.

Answer 10

1. the object can come into contact with the ground
2. the object can sit in the air for a long period of time.
3. the object can be brought near an oppositely charged object

Question 11

What would happen if e- was rubbed onto an insulator?

Answer 11

If rubbed onto an insulator, the e- can’t flow through and will be stuck in place (static energy) on the outside of the material.

Question 12

what is electric current? ho is it measured? what is the symbol and unit?

Answer 12

It is the flow of charge from one location to another.
it is measured by how many electrons flow past a point every second.
symbol : I
unit: amperes

Question 13

What is voltage? What is the symbol and unit?

Answer 13

Voltage (EMF) is the energy (per unit charge) provided to a circuit.
the symbol : V
the unit : volts (V)

Question 14

What is resistance? What is the symbol and unit?

Answer 14

the opposition to electron flow provided by a material.
symbol: R
unit: ohms Ω

Question 15

What is the relationship between the resistance of an object and the current moving through the object?

Answer 15

as the resistance of an object increases, the current moving through the object decreases

Question 16

What are the four factors that affect resistance?

Answer 16

1 material
2 length
3 thickness
4 temperature

Question 17

What is the relationship between voltage (V), current (A) and resistance (R)?

Answer 17

V=IR

Question 18

State the definition, the unit, and the symbol for current. what do you use to measure current?

Answer 18

Electric current is the flow of charge from one location to another.
The unit is: amps (A)
The symbol (I)
An ammeter

Question 19

define resistor?

Answer 19

An object that resists the flow of e- is called a resistor.

Question 20

A light bulb had a resistance of 10 ohms. if the measured current in light bulb is 4A. calculate the voltage across the light bulb.

Answer 20

40A

Question 21

How do you calculate gradient?

Answer 21

y2-y1/x2-x1

Question 22

define potential difference

Answer 22

The potential difference is the energy (per unit charge) that is transformed by a load.

Question 23

What is the law for conservational energy.

Answer 23

The Law of Conservation of Energy states that energy can only be transformed or transferred, but not created or destroyed (except in a nuclear reaction).