1. Mass vs Weight

2. Mass Amount of matter in an object Does NOT change with location
Measured in grams with a balance

3. Weight The force of gravity on an object DOES change with location
Measured in Newtons with a scale
Weight = mass x gravity
Fw = mg
gearth = 9.8 m/s2 (mass must be in kg)
gmoon = 1.6 m/s2
gJupiter = 24.8 m/s2

4. Practice Problems
Your cat has a mass of 2kg. What is her weight in Newtons on Earth?
Fw = mg
Fw = 2kg x 9.8 m/s2
Fw = 19.6 N

5. 2. What is your cat’s weight on the moon? (g = 1.6 m/s2)
Fw = mg
Fw = 2kg x 1.6 m/s2
Fw = 3.2 N

6. 3. What is your cat’s weight on Jupiter? gJupiter = 24.8 m/s2
Fw = mg
Fw = 2kg x 24.8 m/s2
Fw =49.6 N
Same size, same amount of stuff (mass), but different gravity

7. Gravity
Force that acts between any two masses, an attractive force that pulls objects together