P h y s

Question 1

What is the calculation of density, mass and volume?

Answer 1

Density: mass/volume
Mass: density x volume
Volume: mass/density

Question 2

When does pressure occur?

Answer 2

Pressure occurs when force acts on area
Pressure: force/area
Force: pressure x area

Question 3

What s the calculation for the moment of force?

Answer 3

Moment of force: force x distance of pivot

Question 4

What device is used to measure if an object has a negative or positive charge?

Answer 4

Coulombmeter

Question 5

What are fossil fuels?

Answer 5

Stores of chemical energy, e.g coal, oil, natural gas

Question 6

How many types of energy are there and what are they?

Answer 6

• 2 main types of energy

- potential energy (PE) and kinetic energy (KE)

Question 7

Name 8 types of energy

Answer 7

Gravitational potential energy (PE)
Strain energy (PE)
Chemical energy (PE)
Kinetic energy of moving bodies (KE)
Sound energy (KE)
Electrical energy (KE)
Internal energy (KE)
Electromagnetic energy (KE)

Question 8

What device do you use to measure the current and voltage and what is their unit?

Answer 8

Current: device used is ammeter; unit is amp
Voltage: device used is voltmeter; unit is volt

Question 9

What is the law of reflection?

Answer 9

Angle of reflection = angle of incidence

Question 10

What is refraction

Answer 10

Refraction: when light changes its direction

Question 11

Name the colors in the rainbow:

Answer 11

Red
Orange
Yellow
Green
Blue
Indigo
Violet

Question 12

What is friction?

Answer 12

Friction: contact force occurring between 2 surfaces when a push or pull could cause 1 surface to move over the other.
*Static friction: small pushing/pulling force is generated to slide one surface over another.
Sliding friction: if pushing/pulling force is further increased, one surface will slide over the other.

Question 12

What is increasing and reducing friction?

Answer 12

Increasing friction: pressing surfaces makes projections and hollows lock together
Reducing friction: a liquid applied to 2 surfaces fills the hollows and makes contact between surface smoother.

Question 13

What is air resistance?

Answer 13

Air resistance: when an object moves through air, the objects pushes on air and air pushes back with force.

Question 14

What’s the difference between mass and weight?

Answer 14

Mass: the amount of matter in it; measured in g and kg
Weight: the pull of earth’s gravity on the object; measured in newtons (N)
*1kg = 10N
*planets with larger mass will have larger gravitational field strength.

Question 15

What is speed and how do you measure speed?

Answer 15

Speed: measure of distance covered by a moving object in a certain time
Speed = distance/time

Question 16

How do you find the density of. A. Liquid?

Answer 16

1- find mass of cylinder, M1.
2- Pour certain volume into measuring cylinder, V.
3- Find mass of liquid and cylinder, M2.
4- Find mass of liquid, M2-M1 = M1
5- Find density, M1/V

Question 17

How many types of energy resources are there and what are they?

Answer 17

• 2 types of energy resources

- Renewable energy (RE) and non-renewable energy (NRE)

Question 18

Give 8 types of energy resources:

Answer 18

Fossil fuels (NRE) 
Radioactive elements (NRE)
Hydro electric (RE)
Wind (RE)
solar (RE)
Fuel wood (RE)
Geothermal (RE)
Waves (RE)

Question 19

How are the 3 ways that heat or thermal energy move?

Answer 19

Conduction: occurs easily in solids
convection: occurs in liquids/fluids and gasses
Radiation: occurs in space or gas’
Evaporation: particles in liquid have different amount of energy; the higher the. Energy, the faster they move

Question 20

Why are we able to see the moon?

Answer 20

We can see the moon because it reflects the sun’s light; it’s non luminous

Question 21

What is the device you use to measure sound waves?

Answer 21

Oscilloscope

Question 22

What is frequency and amplitude and how do you measure it.

Answer 22

Frequency: the pitch of a sound; measured in Hz
Amplitude: loudness of a sound

Question 23

What is the law of the conservation of energy?

Answer 23

Law of the conversation of energy states that energy cannot be made or destroyed, it can only be changed from one form to another.

Question 24

How do you know if a sound has a soft amplitude or loud amplitude

Answer 24

Soft sound: sound waves are low

Loud sound: sound waves are high

Question 26

How do you know if a sound has a high pitch or low?

Answer 26

High pitch: a lot of sound waves

Low pitch: sound waves are spread out

Question 27

What are the primary and secondary colours?

Answer 27

Primary: red, blue, green
Secondary: cyan, magenta, yellow

Question 28

What is a magnetic material and domains?

Answer 28

Magnetic material: one that’s attracted to a magnet and can be made into a magnet.
Domains: inside magnetic material; many tiny regions that behave like microscopic magnets.

Question 29

When do magnets repel and attract?

Answer 29

Similar poles repel and different poles attract.
E.g. north pole repels north pole
North pole attracts south pole

Question 30

What’s a magnetic field?

Answer 30

Magnetic field: the region around a magnet where pull of magnetic force acts on magnetic material.

Question 31

What is an electromagnet and how does it work?

Answer 31

Electromagnet: made by wrapping wire around iron bar so wire makes a coil.
-when electric current passes through coil, magnetic field from coil turns iron bar into magnet (that can be used to lift things up).

Question 32

If 2 balloons were negatively charged and are brought close together, will it repel or attract?

Answer 32

It will repel just like electrical charges

Question 33

What is an induced charge?

Answer 33

• an induced charge is one that is made in a material by a charged material without 2 materials touching.

Question 34

What”s a series circuit and a parallel circuit?

Answer 34

Series: all components are in line.
Parallel: components are arranged side by side.

Question 35

Which direction does the sun come up and go down from?

Answer 35

• The earth rotates on an axis and the earth rotates once on its axis in a day.
• The sun comes from the east and goes down on the west.