Properties of materials & Earth physics

In which of the following, sound wave travels the fastest?

• Juice

• Metal

• Vacuum

• Nitrogen

Which of these sound waves has the quietest volume?

• 1

• 2

• 3

• 4

When Mr. Tabbert yells his name in a cave, the sound reflects off the walls of the cave and travels back to his ears.  What is this called?

• frequency

• echo

• echolocation

• pitch

How do bats and other animals use echolocation to see?

• They make high pitch sounds that zap their prey.

• They make low pitch sounds that draw their prey to them.

• They make high pitch sounds that bounce off prey and back to them.

• None of the above

A meeting has to take place in a big conference hall. Which one of these materials will help to reduce echoes in the hall?

• Flat wood sheets

• Shiny metal sheets

• Large flat mirrors

• Soft thick curtains

Tim is playing guitar by plucking the strings. How do you think can he make the sound of guitar louder?

• Pluck the string with more force.

• Pluck the string with less force.

• Make the string tighter.

• Make the string looser.

Which layer of the Earth consists of solid iron and nickel in the centre?

• Crust

• Inner Core

• Outer Core

• Mantle

What does the theory of continental drift state?

• The continents were once joined in a super-continent and have moved over time.

• Continents are stationary and do not move.

• The Earth is broken into lithospheric plates that move due to convection currents.

• Earth's tectonic plates move slowly on liquid rock.

Earth's crust is broken up into several large rocky movable pieces called ......................

• folds

• tectonic plates

• faults

• fossils

Complete the sentence.

Earth's plates ..................................

• are constantly moving and changing the face of the Earth

• have never moved

• move seldom and very fast

• move when they feel like it