Page 7 - Class VI Activities Forces and Energy

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Subtopic: 3.7 Where does Energy go?

Ac+vity: Ripple Tanks Inves+ga+on

Learning Objec+ve:- To understand that energy tends to dissipate and, in doing so, it becomes less
useful.

Materials required:- A shallow waterproof rectangular tray (about 40 cm × 20 cm × 5 cm), water,
a ruler.

Procedure:-

1. Fill the tray with water to a depth of about 1 cm.
2. Liw one short edge of the tray slightly and drop it gently to create a wave.
3. Observe and count how many )mes the wave travels back and forth un)l it stops.
4. Change the water depth and repeat the experiment.
o Does the wave travel more or fewer )mes?
5. Try again by liwing and dropping one long edge of the
tray.

o Does the wave travel farther in this direc)on?

Conclusion
As the wave moves back and forth across the tray, it
gradually loses strength and eventually disappears. This
shows that energy is gradually lost (wasted) as the wave
travels through the water.

Assessment Ques+ons:
1. State one variable that must remain the same when you change the direc)on of the wave.
2. Which way (along or across the tray) does the wave travel the longest total distance?
3. Name the energy that is stored by the wave as it moves.

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