Chapter 6 Flashcards
What is one property of all soundwaves
They can be reflected from surfaces
Is sound wave affected by gravity?
No
Which type of surfaces do sound waves best reflect from
large,smooth and flat surfaces
What is the reflection of a sound wave called?
The reflection of a sound wave is called an echo
What happens if you clap in an empty room
The sound wave will travel away from your hands in all directions and the sound of clap seems to last longer than usual before fading away.
Which animal uses echo to find insects for food?
Bats
How do bat use echoes to find food?
The bat makes a sound, the sound wave reflects off the insect.
The bat can workout where the insect is from the time taken for the echo to reach the bat and the direction the echo comes from
What do boats use echoes for?
Boats use echoes to find the depth of water under the boat.
How do boats use echoes
A sound is set from the bottom of the boat, the sound travels through the water and reflects off the solid ground and comes back to the boat. The time taken for the echo to come back can be used to work out the depth.
Can echoes be used to make images from inside the body?
Yes
How are echoes used to make images from inside the body?
Sound sent into the mother’s body echo out of her body. This method is used to make the image of the unborn baby.
Explain what is continental drift
millions of years ago, all the land was one large continent, then the land broke up and drifted apart
What are the evidence for Alfred Wegener’s continental drift idea?
-The shapes of the continents fit together
- The types of rock on the different continents match up where they fit together
-The fossils on the different continents match up where they fit together
What are plates under the ocean called?
oceanic plates
Tectonic plates move slowly on the liquid rock called____
magma
What tectonic plates move about _____ per year
4cm
The places where tectonic plates meet are called
Plate boundaries
The movement of tectonic plates creates three type of____
plate boundaries
One plate slide underneath the other one. This is called_____
subduction
What happens during subduction?
The rocks in the Earth’s crust melt as they move into the mantle. They become part of the mantle
What happens as tectonic plates drift away from each other?
They break and crack when they become too thin. Lava erupts from the mantle and hardens to form new crust with new rocks. This causes a volcano.
What happens when plates slide past each other due to large friction and pressure building up?
This can cause an earthquake
When tectonic plates move together, the rocks crumple and fold upwards. The mountains that this produces are called_____
fold mountains
What is the liquid rock when it is underground called
magma
What is the liquid rock when it is on the surface called?
Lava
Where are volcanoes usually formed
Volcanoes are usually formed at the plate boundaries when magma from the mantle rises up through the cracks in the Earth’s crust.
Why do volcanoes get bigger each time it erupts
The lava and ash harden as they cool to form new rocks.
Violent volcano eruptions can even cause___
avalanches, earthquakes and tsunami if the volcano is close to the sea
When do solar eclipse happen
when the Moon comes between the Sun and the Earth
What does opaque mean
Opaque is used to describe objects that do not let light pass through
Draw the Diagram of a solar eclipse
pg 224
Draw the picture of the solar eclipse in order (12 patterns)
pg 224
Draw the diagram of a lunar eclipse
pg 225
What is required that only eclipses can happen
Sun,Earth and Moon are in the same straight line
