Grade 4 Light
Name three natural sources of light.
- fireflies
- lightning
- stars
- sun
- fire
What is a vibration?
vibrations are invisible waves that move up and down very quickly.
They are what make sound.
What province do we live in?
Ontario
Name three examples of natural forces
landslides, tornadoes, hurricane, earthquake
What is a force?
A push or pull acting on an object.
Name three examples of artificial sources of light.
- light bulb, i-pad, flash light
Name a high-pitched sound
cricket, mouse,
Give an example of a light source that also gives off heat.
fire, candle,
Name three types of force
magnetic
muscular
electrostatic
gravity
What metal is not attracted to a magnet?
nickel, iron, gold or steel
gold
Give three examples of opaque objects.
- wood
- desk
- couch
measures the number of sound vibrations per second.
frequency
What is the speed of light?
300,000 kilometres per hour
Name 2 safety devices that help the impact of a force
- life jacket, seat belt, helmet
a) sliding down a slide
b) car tires driving on a road
b
occurs when light stops at the object and does not reflect
absorption
Give an example of a material that reflects sound.
- metal, wood, concrete
Name a low- pitched sound
bass drum
The force that pulls objects toward the earth.
gravity
The force that acts on objects that rub against each other
friction
occurs when light bounces off the surface of a material.
reflection
a word that describes how humans hear pressure from sound
loudness
Give two examples of materials that absorb sound.
- wool sweater, foam, cotton, blankets
The force that attracts metals.
magnetism
lightning is an example of what type of force?
electrostatic