Food Chain and Food Web (Ecosystem) EVS, B. Pharmacy 1st Year, Sem-II
Gravity
1. Gravity
1. Gravity requires air/atmosphere.
2. The strength of a gravitational force depends
on the mass of objects.
3. ALL objects in the Universe attract each
other through gravitational force.
4. The farther you get from Earth, the less you
are affected by its gravity.
5. When dropped, all objects fall to Earth at a
constant rate.
3. Gravity
• True or false: Gravity is a force that pulls
things to the center of Earth.
– Is this ALWAYS true?
4. Gravity
• Gravity is a force of attraction between
objects due to their masses.
– ALL matter has mass, so ALL objects
experience an attraction toward ALL other
objects.
5. Weight vs. Mass
• Mass and Weight
Based on the illustration, what are the differences
between mass and weight on the moon and Earth?
Earth
Moon
6. Weight vs. Mass
• Weight is a measure of the gravitational
force exerted on an object.
– Weight changes as gravity changes.
• Mass is the amount of matter in an
object.
– Mass NEVER changes.
7. Weight, Gravity and Mass
___________ is determined by
___________ which is caused by an
object’s ___________.
Complete the sentence below using the
following words: Gravity Mass Weight
8. Gravity
• Newton’s Law of Universal Gravitation
– ALL objects in the Universe attract each other
through gravitational force.
9. Gravity
• 3 Key Facts:
1. Gravitational force is small between
objects with small masses.
This is why you aren’t pulled toward your desk.
10. Gravity
• 3 Key Facts:
2. Gravitational force is larger between
objects with larger masses.
This is why the planets stay in orbit around
the sun.
11. Gravity
• 3 Key Facts:
3. Gravitational force decreases as distance
increases.
The closer you get to
Earth (or any other
object) the stronger
the force of gravity.
What’s the opposite?
12. Gravity Review
• 3 Key Facts:
1. Gravitational force is ________ between
objects with small ________.
2. Gravitational force is _______ between
objects with larger ________.
3. Gravitational force _________ as distance
_________.
13. Gravity
1. Gravity requires air/atmosphere.
2. The strength of a gravitational force depends
on the mass of objects.
3. ALL objects in the Universe attract each
other through gravitational force.
4. The farther you get from Earth, the less you
are affected by its gravity.
5. When dropped, all objects fall to Earth at a
constant rate.
FALSE!
TRUE!
TRUE!
TRUE!
???
14. Gravity
What is the pattern?
9.8, 19.6, 29.4, 39.2, 49
Acceleration Due to Gravity
15. Gravity
• Scientific fact: Due to the force of the
Earth’s gravity, when dropped, ALL
objects accelerate towards the ground at a
constant rate of 9.8m/s/s (or m/s2)
Time (s) Speed (m/s)
1 9.8
2 19.6
3 29.4
4 39.2
Acceleration Due to Gravity
19. Gravity
Acceleration Due to Gravity
• Scientific fact: Due to the force of the
Earth’s gravity, when dropped, ALL
objects accelerate towards the ground at a
constant rate of 9.8 m/s/s
• However, due to air resistance caused by
the force of friction between the air and the
falling object, not all objects on Earth fall at
the same rate.
20. Gravity
Acceleration due to Gravity:
• Earth = 9.8 m/s2
• Moon = 1.6 m/s2
• Neptune = 14.0 m/s2
• Saturn = 12.0 m/s2
Where would you fall the fastest? The
slowest?
