8th Grade Science Review

Which of Newton's laws of motion explains why you must lift a cup if you want to drink from it?

• 1st law--An object at rest will stay at rest and an object in motion will remain in motion unless a force acts upon it.
• 2nd law--The amount of force needed to move an object depends on its mass and acceleration.
• 3rd law--For every action there is an equal and opposite reaction
• 4th law--Gravity depends on mass and distance

Minerals have several properties including color.  What does its color depend on?

• its lustre
• its streak
• its hardness
• its composition (the chemical it's made of)

Where are earthquakes most likely to occur?

• In the middle of plates
• In the oceans
• Along plate boundaries
• Anywhere on the Earth

Why does the Earth orbit the Sun and not a planet in the solar system?

• The Sun is more massive than the planets so it's mass causes the gravitational pull.
• It just happened that way.
• The Earth pulls the Sun toward it  because it is so massive.
• The Earth is closer than the other planets so the distance causes the gravitational pull.

Some objects like the Sun produce their own light.  Others don't.  Why can we see objects that don't produce light?

• They absorb the light.
• They reflect the light.
• They transmit the light.
• They bounce the light around until it strikes our eyes.

What kind of fossil preserves evidence of an organism but does not fossilize the body. Shells and footprints that are filled with minerals are two examples of these kinds of fossils.

• cast
• mold
• trace
• There is no fossil like this.

Suppose you jump off a the front of a skateboard.  What are the action and reaction forces between you and the skateboard?

• The skateboard provides the action force and you react by jumping forward.
• There are two action forces and no reaction forces in this example.
• You provide the action force and the boat reacts by moving backwards.
• The forces are equal and opposite.  There's no action and reaction force.

Which is an example of refraction?

• You look at yourself in a mirror.
• You look out the window and see your friend on the other side.
• You take a picture with your phone.
• You shine a light through a prism, it bends and a rainbow can be seen when the light exits the prism.

What's a mid-ocean ridge?

• An underwater mountain range formed where two plates collide. 
• An underwater mountain range formed where two plates slide past each other.
• An underwater mountain range formed where two plates subduct.
• An underwater mountain range formed where two plates separate.

The main element that makes up stars is _________.

• Hydrogen
• Helium
• Nitrogen
• Oxygen