Candle Flame and Spiral Experiment

In this activity, work in groups of fives or sixes to carry out the experiment on energy changes.

Aim: To observe a series of energy changes.

Materials you need:

• Spiral made from cardboard.
• String ( about 10cm long)
• Retort stand
• Candle
• Matches
• Scissors

Method and results:

(a)  Cut along the circular line drawn on the cardboard to make a spiral.

(b)  Tie one end of the string through the hole in the cardboard and the other end to the retort stand.

(c)  Place a candle below the spiral so that it is about 10cm above the candle (see figure below).

    

(d)  Light the candle and observe what happens to the spiral.

( Caution: Do not allow the spiral to touch the candle!)

What have you learnt from the experiment?

(a)  Explain what happened to the spiral ?

________________________________________________________

            ________________________________________________________

            ________________________________________________________

            ________________________________________________________

(b)  Trace the energy changes that caused the change in the spiral by  

       filling in the blanks below.

           

___________________ energy in _______________             _________________ and ___________________ energy in candle flame _______________ energy in the air  Kinetic energy in the _____________________ ________________ energy in the spiral.

 

Energy Conversions

The picture below shows a wind-up toy duck. In your groups of fives or sixes, carry out an experiment to find out if the number of turns the key of the wind-up toy is wound will affect the time taken for it to stop moving. You will need a wind-up toy and a stop-watch for this activity.

                                      

 Method:

(1) Wind the key of the wind-up toy one complete turn.

(2) Place the wind-up toy on the table.

(3) Start timing the wind-up toy with a stop-watch once it starts to move on the table.

(4) Stop timing once the wind-up toy stops moving.

(5) Record the time shown on the stop watch. Repeat steps (1) to (4) and find its average reading.

(6) Repeat steps (1) to (5) by winding the key with 2 and 3 complete  

     turns respectively.

(a) Record your findings on the table below.

	Time taken (1st reading)	Time taken (2nd reading)	Average time taken
1 turn
2 turns
3 turns

(b)   What is the relationship between the number of turns  of the key and  

     the time taken for the wind-up toy to stop moving? Explain your answer.

________________________________________________________

________________________________________________________

Burning of Candle Wax  Experiment

What have you learnt?

3a)      Explain what happened to the candle wax?

            ________________________________________________________

            ________________________________________________________

3b)      Trace the energy changes that caused the change in the candle wax by filling in the blanks below:

_____________ energy in ________________              ___________________ energy in ___________              ______________ energy in ____________             _____________ energy in candle

 

  

Trace the energy changes in the following examples by filling in the blanks.

A book falling off a shelf and onto the ground.

 

1.

     ________________________ energy           __________________ energy

     + _________________ energy

Wind chimes ringing in the wind.

 

2.

     ___________________ energy              ________________ energy

A battery-operated music disc player playing a song.

 

3.

     _________________ energy            ___________________ energy

                 ___________________ energy

A boy shooting water out from a toy water pistol.

 

4.

     __________________ energy             __________________ energy

Solar-powered lamp giving out light at night.

 

5.

 

     Energy from the ____________  in the day             _______________

    energy at night

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