In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factorsIn physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factorsIn physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factorsIn physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factorsIn physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors

1. Opening
Prayer

2. STATES of ENERGY
Potential Energy
- energyatrest
- storedenergy
Potential energy is the energy
possessed by an object as a
result of its POSITION or
CONDITION.

3. 3
Gravitational PE
• Can be calculated with:
PE = mass  acceleration  distance above
ground level
PE = m  a  d
Units:
[J] [kg] [m/s2] [m]
SI Units of GPE : Joule [J]

4. 3 types of Potential energy
1. Elastic potential energy
Robert Hooke -discovered that
elastic objects, such as metal springs,
stretch in proportion to the force that acts on
them.
𝑊=𝑃𝐸=
1
2
𝑘𝑥2
2. Chemical potential energy
3. Gravitational potential energy

5. • The higher the object is from the
ground, the greater is its
potential energy; the more
massive an object is, the greater
is its potential energy.

6. 6
Example of GPE
• You lifted your bags to the top of your table.
What can you say about the GPE of your bag?
– Zero, increase, decrease
• Lift the same bag on the Moon. What happens to
GPE?
– Zero, increase, decrease
• Will the GPE be the same on Earth and Moon?
– Same, less on Moon, more on Moon?

7. Sample Problem
1. A 2kg object is lifted to a
height of 2 meters. What is the
P.E. of this object?

8. 8
Sample Problem
• You lifted a set of books of mass 3kg, for 2m. What
is the PE gained by the books?
• Find the work done by you to lift the books.
PE = mad
= 3kg  9.8m/s2  2m
= 58.8 J
Work done, W = F  d (F = weight of books)
= (m  a)  d
= 3kg  9.8m/s2  2m
= 58.8 J (Note: same as GPE)

9. Question 1
Calculate the PE gained
when a weightlifter lifts a
mass of 120kg up by 2.5m.
GPE = m x a x d
= 120kg x 9.8 m/s2 x 2.5m
GPE = 2940 J

10. Question 2
Calculate the potential energy gained by a
student of mass 70kg climbing a flight of
stairs of height 4m.
PE = m x a x d
= 70kg x 9.8 m/s2 x 4m
GPE = 2744 J

11. POTENTIAL ENERGY
1. A 30 kg child climbs 15 meters
up a tree. When he stop to have
a look around, what is the
child’s P.E.?
2. A ball with a mass 1 kg is
dropped from a height of 50 m.
What is the P.E. of the ball?

12. POTENTIAL ENERGY
3. The mass of the boulder is 150
kg and the height to which it
mass lifted is 5 m. How much
energy does the boulder has?
4. A 2 kg mass falls 4 m. Find the
P.E. lost.
5. A body has 245 J of energy
when lifted to a height of 5 m.
Find the mass of the body.

13. COMPARISON

14. Kinetic vs. Potential Energy
At the point of maximum potential energy, the car
has minimum kinetic energy.

16. Assignment
Bring the following materials for the activity –
based experiment next meeting:
• Meter stick
• Timer

18. ALL RIGHTS RESERVED
Reproduction or redistribution of all, or
part, of this presentation without
written permission is prohibited.
Instructional Materials Service
Antipolo National High School
1870 Antipolo City
Science Department, (+632) 408-80-03
CHRISTIAN A. VIERNES
Author
christianviernes1004@yahoo.com
2013