GRAVITY NOTES

Gravity is the force of attraction between all masses in the universe.
The gravitational force depends on the MASS of the objects and the DISTANCE the
objects are from each other.
Greater mass = greater gravity
Longer distance = less gravity
Anything with mass has gravity.
Mass vs. weight
Mass
 Measures the amount of MATTER in an object
 Measured in grams (g) or kilograms (kg)
 Does NOT change with location
Weight
 Measures the PULL of GRAVITY on an object
 Measured in NEWTONS (N) or POUNDS (lbs)
 Changes with an object’s location.
What determines the strength of gravity’s pull?
MASS
ALL objects with mass have gravity. The more mass something has, the
more gravity it has. This force is difficult to measure unless one ofthe objects has a very large mass.
DISTANCE
The closer two objects are, the more gravitational force they will exert on each other.
Planets and gravity
More massive planets have more gravity.
 The weight of an object will change from planet to planet
Which of the following best explains the data for mass of the golf balls?
 A. the matter in the golf balls did not change on each planet
 B. the volume of the gold balls did not change on each planet
 C. the size of the planets was the same
 D. gravity on each planet was different because the planets were different sizes.
Application to real life
Buildings, bridges, even chairs must be designed to withstand the force of gravity.