3. Aims
The aim of the lesson was
to acknowledge the
students with general
principles of
energy conservation,
physical formulae and their
practical implementation.
4. Proceedings
The lesson was divided into three parts:
theoretical
practical (experiments)
workshop (exercises)
5. Proceedings
Part I
The pupils
were acquainted
with the theory
of the issue and
its terminology in
the English
language.
The teacher
used an interactive
whiteboard.
6. Proceedings
Part I
We gained theoretical
knowledge regarding energy
exchange and learnt about its
practical implementation.
7. Lesson Proceedings
The teacher presented experiments to illustrate
the existence of mechanical energy exchanges
in every day life.
Part II
8. Lesson Proceeding
- experiment no 1
‘The jumper’ is a toy which is used
to present the law of conservation
of energy as well as the exchange of
inner energy into kinetic and potential
energy of a physical body.
Jumper
9. Lesson Proceedings
- Experiment no 2
This experiment
by means
of a watermill
describes
the way energy
exchange might
be utilized.
10. Lesson Proceedings
Part III
The next step included exercises
and solving tasks checking
the students’ knowledge.
11. Lesson Proceedings
Part III
Example exercise:
Using the law of conservation
energy, calculate the altitude a physical
body will reach if thrown vertically with
a velocity of …
12. Lesson Proceedings
Part III
Sample task:
From the tower of 25 m in height a stone
has been thrown upwards with the initial
velocity of 20 m/s. Calculate the time it takes
to hit the ground, granted that the
acceleration of gravity g= 10 ms-2. If
the acceleration of gravity equals 10
m⋅s-2, then the stone will hit the ground
after the time approximately equals: ………
14. Test
Projections in gravitational field – energy
exchanges
Task 1 Mechanical energy unit can be expressed
in International System of Units (SI):
2
kg ⋅ m 2 2 m
a) 2
b) kg c) kg ⋅ m 2
s s
d) dimensionless quantity.
Task 2 Kinetic energy increases and potential declines when
a physical body:
a) Is projected horizontally with an initial velocity
b) Is falling freely
c) Is projected vertically upwards with an initial velocity
d) Is projected at certain angle with an initial velocity
15. Test
Task 3 The time of free fall from the altitude h, is expressed
by the following phrase:
a) free time b) time of fall
c) free velocity d) acceleration
Task 4 In vertical projection upwards, the maximum velocity
of the physical body is calculated with the following formula:
gt V02 V0
a)
h= b)
h=
c)
h = 2 gt
d) h=
2 2g 2 gt
Task 5 The range in oblique projection is calculated with
the following formula:
V02 sin 2 2ε V02 sin 2α cos α
a) Z = 2 gh b) Z = c) Z = d) Z =
g g 2th
16. Test
Task 6 In vertical projection upwards the mechanical energy
changes
according to the following rule:
a) Kinetic energy declines and potential energy increases
up to the point of reaching the maximum altitude
b) Potential and kinetic energies are constant during the time
of motion
c) Potential energy equals zero and kinetic energy increases
d) Potential energy decreases and kinetic energy grows
Task 7 The following formula + E
Em = W describes mechanical energy :Ek
Em = E p +
k
a) b)
mV 2
c) Em = + mgh c) Em = const
2
17. Test
Task 8 Which sentence(s) is/are false:
a) A physical body thrown upwards is subject to uniformly retarded
linear motion.
b) In oblique projection the range of a physical body always equals
the maximum altitude the body reaches.
c) A freely falling physical body is subject to uniformly linear
motion.
d) The law of conservation of mechanical energy does not apply
to horizontal projection.
Task 9 Match the following terms and formulae:
m
a) conservation of mechanical 1) g = 9,81
s2
energy 1
2) Ek = mV
2
b) Kinetic energy
2
c) Potential energy 3) Em = const
d) Gravitational acceleration 4) E p = mgh
18. Test
Task 10 The trajectory of an moving object during horizontal
projection is:
a) A straight line
b) A sector of parabola
c) A hyperbole
d) A circle
Task 11 Using the law of conservation of mechanical energy
calculate the final velocity of a physical body which is falling down
from the altitude of 10 m. Air resistance should be ignored.
19. Test - results
SCORE PERCENT NUMBER OF STUDENTS
13/15 87% 3
12/15 80% 2
11/15 73% 5
10/15 66% 6
9/15 60% 3
20. Test - conclusions
The results of the test proved that
the pupils learned the lesson on a good
level.
They were especially interested
in the parts of the lesson and the test
which were done in English.
21. Evaluating survey
1. The lesson made me understand English
better.
2. The lesson made me speak English easily.
3. The lesson made me learn the English
language more easily.
22. Evaluating survey
4. The lesson made me write in English more
easily.
5. I would prefer the lesson in another
language.
6. The lesson was interesting because it was
in English.
23. Evaluating survey
7. The lesson made me understand the
meaning of the English language better.
8. I would like more lessons in English.
9. ………………………………………………..
(other – please write in English)
26. Evaluating survey
- conclusions
The pupils express strong interest
in the lesson carried out in English,
however some of them have minor
difficulties with perception.
27. Summary
The pupils were interested in the lesson
and learned it on a good level.
They can use theoretical knowledge
in practice and they are willing to take
part in lessons carried out in English.
29. Exercise
1. A globule of 100g mass is falling freely
from the aptitude of 5m. Calculate
the globule kinetic energy at the time
of hitting the ground. Assume g =
10m/s2
2. What altitude reaches the ball of 50g
mass, thrown vertically upwards with initial
velocity Vo=10m/s. Assume g = 10m/s2
