Gravity
How Distance and Mass
Affect Gravity
Gravity
• Any object with mass exerts a force of gravity that
pulls on objects around it.
• The more mass an object has, the greater its pull
of gravity.
• Gravity keeps you from floating off into space.
Gravity helps keep the moon in orbit around the
Earth.
• Gravity also keeps the Earth in orbit around the
Sun.
Gravity
• Just as you are attracted to Earth, Earth is
attracted to you. You notice only the force that
Earth exerts on you because the force you exert
on Earth is so much smaller.
• The force of gravity depends on two factors:
mass and distance.
Gravity
• Think about an apple falling from
a tree on Earth. Both the apple
and the Earth pull on each other
because they both have mass.
But the apple’s mass is so small,
its force of gravity is very small.
It does not pull very strongly on
Earth.
Gravity
• Earth has much more mass than the apple. That
means that Earth’s force of gravity is larger than
the apple’s force of gravity. Earth’s gravity pulls
the apple down to the ground. As the apple falls,
its gravity actually pulls Earth up a very small
distance. But Earth moves only the tiniest amount
because Earth’s pull is so much greater than that
of the apple.
Distance and Gravity
• As objects move closer together, their pull on
each other grows stronger.
• As objects move farther apart, their pull on
each other weakens.
Gravity
• Think of a spacecraft traveling toward another
planet. As the spacecraft moves away from
Earth, Earth’s pull on it decreases. As the
spacecraft moves closer to the other planet, that
planet’s pull on the spacecraft increases.
Gravity – Distance and Mass
HEAVENLY BODIES
SUN
EARTH
MOON
MERCURY
VENUS
JUPITER
SATURN
URANUS
NEPTUNE
GRAVITY
28
1
0.16
0.38
0.91
2.6
1.07
0.91
1.1
YOUR WEIGHT
(35 KILOS)
HOW TO FIND YOUR WEIGHT?
• The formula is:
ACTUAL WEIGHT IN A HEAVENLY BODY=
WEIGHT ON EARTH x GRAVITY OF HEAVENLY BODY
Watch the video segment on
Discovery Education called: Gravity
https://app.discoveryeducation.com/learn/videos/
4e9c69c5-6557-424d-9d4023e68ab5d970?hasLocalHost=false
Watch: Gravity on Brain Pop
https://www.brainpop.com/science/motionsforces
andtime/gravity/
Watch: Examining Gravity and its Pull
on Discovery Education
https://app.discoveryeducation.com/learn/videos/
b8fd0aaa-0355-4617-acd9b7c08ec61262?hasLocalHost=false
Exit Ticket
1.How does distance affect gravity?
2.How does mass affect gravity?