video clips in education

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Doc. RNDr. VÁCLAV KOUBEK, CSc., Mgr.KARLA HOLÁ aculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, Slovakia o can be a powerful tool for a meaningful learning. ould be motivational because youths tend to love working creative ways with new technologies. an provide both – a common experience for all dents and also highly individualised learning experience using computers. ndividual computer experiences ve proven to be more comprehensive and motivating than ditional group classroom exercises. ed on Power On! Study – Role of Technology in Preparing Children for the 21 st Century.” efer to students’ experience from everyday life.

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Video clips in Education. Doc. RNDr. VÁCLAV KOUBEK, CSc., Mgr.KARLA HOLÁ Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, Slovakia. Video can be a powerful tool for a meaningful learning. could be motivational because youths tend to love working - PowerPoint PPT Presentation

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Page 1: Video  clips  in  Education

Doc. RNDr. VÁCLAV KOUBEK, CSc., Mgr.KARLA HOLÁFaculty of Mathematics, Physics and Informatics, Comenius University,

Bratislava, Slovakia

Video can be a powerful tool for a meaningful learning.

• could be motivational because youths tend to love working in creative ways with new technologies. • can provide both – a common experience for all students and also highly individualised learning experience by using computers.• individual computer experiences have proven to be more comprehensive and motivating than traditional group classroom exercises. (”Based on Power On! Study – Role of Technology in Preparing Children for the 21 st Century.”) • refer to students’ experience from everyday life.

Page 2: Video  clips  in  Education

1 Setting of a physical problem and its analysisA: Series of activities in different branches of Physics

(used in teacher training within seminars but more or less on a high school level)

(Virtual Dub used for replaying and extracting data)B: Data video measurements

(Coach 5 graphical and analytical tools) 2 Depiction of an experimental set-up and measurement itself• aimed as a hint for teachers in service to advise them how to arrange microcomputer based measurements• to be used with teacher trainees as a kind of preparation for Labs in Physics Education• demonstration of an experiment

in teacher training process to be used in distance learning of Physics’ teachers

Usage of video clips at the Department of Physics Education

Page 3: Video  clips  in  Education

HURDLE RACE

Could you determine the average speed of the fastest runner?

Could you estimate what was the delay of other runners and what were their averege speeds?

Also data from the computer measuremnt of time displayed on the screen during the race might help us.

You can use VirtualDub in order to see the clip frame by frame - clip klPREK01.aviYou can use VirtualDub in order to see the clip frame by frame - clip klPREK01.avi

You do not have to be a professional sportsman in order to answer the following question, after the thoughtful view and of the video clip.

What is the length of the track?

Page 4: Video  clips  in  Education

REFLECTION

• Measurement of the position of a billiard ball bouncing on and off from one of the edges of the billiard table and the angle of incidence and reflection of the ball directly by a protractor displayed in Data Video widow. • Possibility of modeling activities, comparison of the received graph with the modeled one.• Measurement of angles of a laser light reflected from a mirror.

• The objective: Formulation of law of reflection

Page 5: Video  clips  in  Education

Is there any connection between the distance of the magnet from the magnetic needle and frequency of its oscillation? Watch the clip.Try to design a physical experiment in order to explore the dependence. Which characteristics of the field would you rely to the period of oscillation of the magnetic needle?

Scheme of the experimental set-up is shown in the figure. The main point rests in the substitution of the magnet of unknown parameters by a solenoid, one -layer coil, carrying electric current I. In the centre of the hollow solenoid there is total magnetic field BT of the magnitude

0T

nIB

l

l - length of the solenoid,n - number of its loops.

MAGNETIC OSCILLATION

See the experimental arrangement in a video clip and measure >> >> >>>> >> >>

Page 6: Video  clips  in  Education

Click the picture and explore the curcuit.

Compare its elements to the scheme in the

previous slide.

Our aim is to find out the

dependence of period of oscillation

of a magnetic needle on magnetic

field B in the centre of solenoid

hollow. We will measure current I,

carried by solenoid, instead of BT.

0T E T ,

nIB B B B

l

MAGNETIC OSCILLATION

Two signs in front of BE are likely somehow connected to the way of putting the coil into the outer magnetic field of Earth. Could you explain it?

Page 7: Video  clips  in  Education

Our further experimental study of the dependence T = T(B), is based on an analogy of the mathematic description of a pendulum oscillating in homogeneous gravitation field g and a magnetic needle in a homogeneous magnetic field B.

BT + BE = K T--2

ET

kTB B

Note:It is necessary to point out that an analogy is based only on the similar shape of the mathematic relations, while the physical background of the two fields - magnetic and gravitational is different.

MAGNETIC OSCILLATION

0T E T ,

nIB B B B

l

Let´s measure! >> >>

Period of oscillation of a pendulum in a homogenous

gravitation field

Period of oscillation of a magnetic needle in a homogenous magnetic field

Page 8: Video  clips  in  Education

Aim: T = T(B)? in the centre of the

hollow solenoid.

Click the photo, put down various

values of electric current and

observe the subsequent change in

the period of oscillation. Measure T

and fill in the table by (I, T) pairs.

In this part of our experiment besides observing we will also measure and analyse the obtained results. We know that the following relation should hold: BT + BE = K T--2

Graphical verification of the relation

BT + BE = K T--2

can be based on linearization of the graph. We shall make pairs (BT, T--2 ). You can check that the graph of BT = K T--2 - BE really does not pass the centre of co-ordinates but you can measure the value of BE at it.

MAGNETIC OSCILLATION

T--2

Other Other examplesexamples

Other Other examplesexamples

Page 9: Video  clips  in  Education

The video clip shows a duplicate of one of the first attempts for flight. A) Explain, why the balloon can float, or even go up.

B) What the crew shall do in order to land?

C) Besides the hot-air balloons there exist also other ones. What can be their filling?

D) Make up your own balloon of a sack using hair dryer.

BALLOON

Czech Prof. F. Běhounek, physicist and writer of sci-fi novels, in one of his novel made his heroes travel in an airship, which was instead of gas was filled by vacuum. It must have had thick construction, of extremely light metal and must have carried powerful air-pumps. Is it possible? Let´s create and investigate the mathematic model. The questions to answer:

1. Will the spherical balloon fly, having thick walls and filled by diluted air?

2. What should be the radius of the spherical part of the balloon?

Page 10: Video  clips  in  Education

Model of the vacuum balloon considers sphere of radius r and the cubic cabin of side a, coefficient of air dilution P = 0,1 of atmospheric pressure.

We search for the total force acting on the balloon F = F (r), depending on the radius r.

This force equals sum of weight and buoyancy force. Weight is determined by the total mass of the balloon, which is given by the sum of mass of the cover, mass of the diluted air and mass of the cabin.

Buoyancy force depends on the volume of the balloon and the cabin.

BALLOON - Model

With the increasing radius of the spherical balloon, buoyancy force rises as well. At the radius equal to 30 m , the balloon is able to hover.

Page 11: Video  clips  in  Education

•The objective: students will find out themselves the relation between angular and peripheral velocity and radius of the observed points. • They could form hypotheses in advance and then check it by extracting the particular information from graphical functions.• Activity is also supplied by the already prepared, measured graphs and an explanatory text with answers to the laid questions.

CLOCK

•Study of circular motion of the two outermost, opposite, parts of a second hand of the clock.

Page 12: Video  clips  in  Education

ADJUSTABLE RESISTOR Study properties of a restotat with the Study properties of a restotat with the total resistance of total resistance of 13 13 A)A) Measure the diameter of the cylinder, Measure the diameter of the cylinder, at which the wire is wound up. Calculate at which the wire is wound up. Calculate the length of one loop of the wire. the length of one loop of the wire. Measure the diameter of the wire. Think Measure the diameter of the wire. Think of another measurement necessary to of another measurement necessary to perform in order to identify material, the perform in order to identify material, the wire is made of. (with the aid of physical wire is made of. (with the aid of physical tables.) tables.)

B)B) Determine the resitance of one loop of Determine the resitance of one loop of the reostat. Think of the total resistance in the reostat. Think of the total resistance in the circuit, if we change the position of the circuit, if we change the position of the rider of the reostat so that electric the rider of the reostat so that electric current is carried gradually through ten, current is carried gradually through ten, twenty, thirty loops. twenty, thirty loops.

C) Plan and perform an experiment to verify that if you double (treble, quadruple,…) the length of the wire included in a circuit, electric current changes into one half (third, quarter,...) of its original value.

D) What is the resistance of a circuit, if the rider is in one fourth from the left end of the spool, in one half and three quarters of the length of the spool?

E) Solve the previous task for the case that reostat clamps 2 and 3 are turned in.

Explain, why the wire winding of the reostat should be of the same constant diameter throughout the whole length of the wire in all the previous tasks.

Page 13: Video  clips  in  Education

HORIZONTAL BAR

Can the gymnast rotate in an arbitrary speed or is there any minimum or maximum period of one rotation?

If you want to measure time in a video-viewer choose klBRADLA02.If you want to measure time in a video-viewer choose klBRADLA02.

The figure shows two physical The figure shows two physical models of the gymnast. models of the gymnast. In the first on we assume that the In the first on we assume that the whole mass of the gymnast is whole mass of the gymnast is concentrated in the centre of concentrated in the centre of mass approximately in the half of mass approximately in the half of her height. her height.

Consider, which of the models is closer to reality and work with it. Do not forget that the motion is not uniform and changes as potential energy is converted into kinetic one and vice versa.

Average height of a female Average height of a female gymnast is about - 160 cm and gymnast is about - 160 cm and mass approximately 45 kg.mass approximately 45 kg.

(referred to its endpoint. )

The second model substitutes the gymnast for The second model substitutes the gymnast for a bar with the moment of inertiaa bar with the moment of inertia 21

3J ml

Page 14: Video  clips  in  Education

RELATIVE SPEED

• Studied on the case of two moving persons. • The objective: students should realise what relative speed is and what the final resultant velocity is in both cases when related to different persons and points in the situation.

• What was the relative velocity of the man and the woman at the beginning of the measurement, at the point, they where passing each other, and at the final measured point?• What are their relative velocities when compared to the velocity of the escalator at the same points?• What are their velocities relative to a person shooting this movie, or just anyone standing aside?• What are their velocities related to the small boy following the woman?

• Does the motion of the cyclist appear to be faster, slower or the same for the walking boy, when compared to the motion of the cyclist from the point of view of a person standing nearby?• What was the relative velocity of the boy and the cyclist at the point, they where passing each other, and at other two points, when they were passing one of the columns.• What formula did you use for calculating of the values of relative speed? • Explain what the negative sign in one of the velocities means.