Weight, Mass, & Volume
What I Know
• What is weight?
• If you traveled to another planet, would you
weight the same?
Weight
• Definition: A measure of the force of gravity
on you.
• Your weight can change if you travel to
another planet or moon.
– Why?
Mass
• Definition: amount of matter in your body.
• Measured in g or Kg
• No matter where you travel, your mass should
stay the same.
MASS and WEIGHT are NOT the same thing!!!!!!!!!!
120kg
120kg x 10 = 1200 N
x Gravity
Mass is the same wherever you are as it is the amount of stuff (particles) that is in you.
Weight is your mass multiplied by the gravitational pull of the planet you are on
On Earth your weight is roughly 10x your mass.
Your weight is a force and is measured in Newtons by scientists.
On the moon the gravitational force is 6 times less than on Earth
120kg
120kg x 1.6 = 200N
x Gravity
The man has lost weight by going to the moon, but what about his mass?
How much would this kid weigh on other planets?
His weight on Earth is 50 Kg.
Place
Gravitational Pull per 1Kg
Calculation
Kid’s weight (N)
Earth
10N
50 x 10 N
500 N
Mars
4N
Jupiter
23N
Pluto
3N
Uranus
11N
Venus
9N
Neptune
10.6N
On the moon
0.1N
In deep space
0N
Copy into your book the table above and calculate your weight
Remember
weight = mass x gravity
ConclusionWhere in the solar system would you weigh the most? How much would you weigh?
Where in the solar system would you weigh the least? How much would you weigh?
Trick Question
What would your mass be on the moon?
What would your mass be on Pluto?
Volume
• Definition: Amount of space that matter takes
up
• Measured in mL, L, or cm3
• Formula:
Length x Width x Height
Find the Volume of These Shapes
Volume of Odd Shapes
• Fill a graduated cylinder.
• Put in your object and record the change in
the height of the water.
Object: rock
What I Now Know
• What is the difference between weight and
mass?
• Why is it useful to know the volume or mass
of an object?