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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