... is the amount of matter that an object has. It's measured in kilograms (kg) or grams (g).
Mass
... is the amount of space an object takes up. It's measured in liters (l) and mililiters (ml).
Volume
Describe three SPECIFIC properties of a classroom item. (Hint: look at the picture)
Hardness, flexibility, buoyancy, elasticity, transparency, permeability, etc.
Density is the relationship between ... and ... of an object.
mass; volume
Explain why the spider, lego, and coin are all in different places in the jar. (Hint: the top liquid is oil and the bottom liquid is water)
Objects float on liquids of a higher density and sink through liquids of lower density. (Coin = more dense than both liquids; spider = less dense than both)
... is the ability an object has to float or sink in liquid or air.
Buoyancy
What are the two forces that act on a falling object?
1) gravity 2) air resistance
True or false? Hang gliders can stay in the air for long periods of time because they have small engines. (Justify your answer!)
False! They stay in the air for a long time because of the large surface area of their wings, which causes great air resistance
Why do some balloons float away when we let go of them?
Helium is a gas that is LESS dense than air and less dense bodies rise
True or false? These two balloons have the same mass. Justify your answer.
False! The one filled with air has a higher mass.
Name the tool we use to measure water when cooking rice.
a measuring cup (jug)
A small rock has a mass of 15 grams and a volume of 3 mL. What is the density of the rock?
D = mass / volume; 15/3 = 5 g/mL
Why do we float more easily in the ocean than in the pool?
Salt water is denser than fresh water; an object will float if it has a lower density than the liquid it's in
Why do hot air ballons rise?
Hot air is less dense than cold air
What two elements does an airplane need to fly?
1) jet engines (to overcome air resistance) 2) wings (curved to make air flow faster over the top)
