Sound

Hi we’ve been learning about sound in science.

What is sound?

Sound is vibrations when something vibrates it makes sound and then it vibrates the air which gets the sound to our ears.

What is echo?

Echo is when the sound bonus of a wall gets into your ear again.

Experiment

In are experiment we knocked on a bunch of surfaces like the wall a desk and the carpet the carpet made the sound quiet the wall no echo and the desk made a loud and echoey sound. this is a video of the project

this is a video about how the ear works

this is a video about sound

 

Fun Facts!

1. Some walls are sound proof which means you can’t hear sound from the other side. They are normally used in things like fireworks.
2. The volume of sound is measured in decibels this is used for things like devise volume.

 

Properties Of Sound

1. Sound is a wave
2. Sound is vibrations
3. Sound moves at different speeds through different things.

 

Hello, this is what are grade 4 science unit has been for 1 week (:

Natural VS Artificial Light

 Natural  light                                    Artificial light

Natural light is light that is not man             Artificial light is light is man-made. Examples of artificial light are:

made. Examples of natural light are:                 light bulbs, fireworks, glow sticks and

the sun, glow worms and fire-flies.                ( some people disagree with this )  candles.

Emitting light vs. reflecting light

Emitting light                                             Reflecting light

Things that emit light create their own light.          Things that reflect light use light from things

Examples of things that emit light are the sun,          that emits light and bouns it back in to your eyes.

TVs and candles.                                                             Egsapls of things that reflect light are desks, chairs,

Things that emit light are luminous carpets and posters.

Things that reflect light are non-luminous

Fun Fact!

Are eyes let in more light wen it’s dark and block of light wen it’s bright.

Light Travelling

This is the first experiment In the experiment we shined a flashlight at the end of a bunch of paper cards. my hypothesis was that the cards at the end would be more lit than the ones at the start because the light would be mostly blocked by the cards and my hypothesis was correct because that is what happened. 

Here’s a photo (click this link)

What’s a good reflector?

In this experiment we had three items ( a smooth mirror, a crumpled piece of tin-foil, white paper and a lack of paper ) we shined a flash light on them and saw how the light hit the wall the mirror was the best. An interesting thing we found was that the light originally hit the white paper.