# 7th GRADE SCIENCE : Article 24 : Potencial energy.

* Activity 2.14   :   Elastic potencial energy.                                             ( 11/13/17   Monday )

ELASTIC POTENCIAL ENERGY.

2.14.a        Toothpicks elastic potencial energy.

and watch out for whats happening.     Notice the aftermath and answer
these questions ( use a piece of paper or a google docs ) :

1)  What has happended to the toothpicks once you added the water?.

2)  How would you explain what has happened?. What do you think about?.

3)  Which way do you think potencial energy has been involved in?.

4)  Where do you think potencial energy was stored in before adding water?.

( 15 points ).

2.14.b        Potencial energy.

5)  What is potencial energy?.

6)  What is then elastic potencial energy?.

7)  Would you change your answers to the some of the previous questions
asked at the activity 2.14.a ?.

8)  What do you think is the difference between the potencial energy involved
in toothpicks activity and the potencial energy involved when you let
drop a ball to the ground?.

9)  Either we consider elastic potencial energy or potencial energy, both
can end and be transformed in a different kind of energy. What is it?.

( 10 points ).

* Activity 2.15   :   Energy, forces and motion.                                             ( 11/14/17   Tuesday )

2.15.a    Transferring potential energy into kinetic energy throughout centrifugal force.

Follow the instructions given by your teacher in order to set up
the device using the Straw, the balloon, tape and paper clip.

When you have it ready, watch out what happens when you blow
it up. After finishing, answer the following questions.

( 10 points ).

2.15.b   When finished the experience, answer the following questions :

a) Which is the energy you used to make the device move?.

b) After blowing the balloon, what is the energy obtained when moving?.

c)  What is the force used for blowing the balloon?.

d)  What kind of force is making the device spin when air withdraws from
the balloon?.

e)  How many kind of energies and forces are involved in this experience?.
Name them.

( 10 points ).

* Activity 2.16   :   Balloon spinner questions .                                       ( 11/15/17   Wednesday )

2.16.a   Do and answer the following questions  yesterday you couldnt do :

a) Which is the energy you used to make the device move?.

b) After blowing the balloon, what is the energy obtained when moving?.

c)  What is the force used for blowing the balloon?.

d)  What kind of force is making the device spin when air withdraws from
the balloon?.

e)  How many kind of energies and forces are involved in this experience?.
Name them.

( 10 points ).

a) What does gravity have to do with the potential energy?.

b) In what direction is always going gravity?.

c) Do all the things fall at the same speed?

Why?   Who demonstrated that?.

d) Why was the Pissa tower important to demostrate gravity and the
same speed all objects fall down to earth?.

e) Who was Galileo?.

f)  What GPE means?

Explain what you think GPE is with your own words.

g) How many kinds of potential energy can we have?   Check it here !!

Summarize the most important of each of them.

i) Draw the Pissa tower and two objects falling at the same time just
as Galileo did in his experiment.

( 10 points ).

2.16.e        >  Here you have a brief outline about what potential energy is :

Potential Energy is the stored energy of an object given its position relative to a body. Gravitational potential energy is one type of potential energy and is equal to the product of the objects mass (m), the acceleration caused by gravity (g), and the objects height (h) as distance from the surface of the ground (the body).

GPE = 3kg * 9.8m/s2 * 5m = 490J       (490 Joules ).

* Activity 2.17   :   Reviewing and working out potential energy .            ( 11/16/17   Thursday )

2.17.a    Read and check the following information. After that, use the formula to
work out the potential energy at the following wordings: (use a google docs).

1)  A stone falling from a building 250m high.

2)  A child of 50kg falling after jumping up until 0.6m high.

3)  A beisball falling after being thrown from 25m high.

Potential Energy is the stored energy of an object given its position relative to a body. Gravitational potential energy is one type of potential energy and is equal to the product of the objects mass (m), the acceleration caused by gravity (g), and the objects height (h) as distance from the surface of the ground (the body).

GPE = 3kg * 9.8m/s2 * 5m = 490J       (490 Joules ).

( 5 points ).

2.17.b    Do the papers and word search given to you today.

( 10 points ).

* Activity 2.18   :   Potential and kinetic energies' Test .                           ( 11/17/17   Friday )

2.18.a   Open a google docs and copy  these questions and answer them.

Choose the best answer to each of the following questions. Good luck!
1. Niagara Falls is a good example of :
a. Kinetic energy being transformed into potential energy
b. Potential energy being transformed into kinetic energy
c. Energy being lost
d. Energy being created.
2. When energy moves from one form to another it is said to be _______________________.
a. Transfixed
b. Transformed
c. Eliminated
d. Lost.
.

3. On a day when the air is still a windmill still possesses
a. potential energy
b. kinetic energy
c. chemical energy
d. gravitational energy

4. The energy associated with motion is called
a. Kinetic energy
b. Elastic potential energy
c. Gravitational potential energy
d. Nuclear.

5.Moving water can be used to produce electricity because
a. Most forms of energy can be converted into other forms.
b. Energy cannot be converted into other forms.
c. Potential energy can be converted into kinetic energy, but not vice
versa.
d. Kinetic energy can be converted into potential energy, but not vice
versa.

6. Which of the following has kinetic energy?.

a. A rock poised for a fall
b. An archers bow that is drawn back
c. A rolling bowling ball
d. A car waiting at a red light

7. Unlike kinetic energy, potential energy is
a. Energy of motion
b. Stored
c. Conserved
d. Not measurable
8. Potential energy that depends on height is called
a. Kinetic energy
b. Gravitational potential energy
c. Elastic potential energy
d. Mechanical energy
9. What type of energy does a spinning turbine have?.

a. Electrical energy.
b. Nuclear energy.
c. Thermal energy.
d. Kinetic energy.

10. What is energy?

A. The ability to react chemically.
B. Anything on the periodic table.
C. The ability to change matter.
D. Only things that are moving have energy.

11. How are potential energy and kinetic energy different?

A. Potential energy is stored energy and kinetic energy is energy of motion.
B. Potential energy is energy of motion and kinetic energy is stored energy.
C. Potential energy is thermal energy and kinetic energy is radiant energy.
D. Potential energy is gravity and kinetic energy is chemistry.

12. Imagine a man bowling. In this case the bowling ball has

A. Potential
B. Kinetic
D. Nuclear                      ( 10 points ).

2.18.b     Go to this LINK, make play and do the  QUIZ .

( 10 points ).

2.18.c   Look up the questions at the following link. Copy them and