Waves Lab

Guiding Question:

How does a floating object lying on the water interact with the waves?

Hypothesis:

If the waves are stronger, then the floating object will move in a stronger way.

Materials:

1. Metal tub
2. Water
3. Food color
4. Floating object (plastic cup)
5. Plastic bottle (Half a liter)
6. Marker
7. Paper and pencil (to record the data)
8. Computer (for processing data)

Procedure:

1. Take a big tub and place it on flat table (far away from the edge so it doesn’t fall).
2. Fill half of the tub with water (don’t fill it too much, because your waves might be so strong that you can spill your water!).
3. Add to the water a few drops of food color so the waves would be more obvious to see.
4. Pick an object that can float on water, for example a cup from the plastic bottle, and place it on the water surface, somewhere in the middle.
5. Take a thin pen to create a small wave.
6. Observe and record on your paper what is happening with the floating object!
7. Take a plastic bottle to create a wave.
8. Repeat the steps for creating a wave.

Data Table:



Analysis of Data:

As you can see from the data table above, the strength of the disturbance will not affect the position of the floating object in a big manner. The strength of the waves (its’ amplitude) will only affect how the object shakes, whether it goes more or less up and down, but not in the direction of the moving of the wave.

Conclusion:

What happened? What did the cup do, was it moving or was it just standing in one place and shaking?
After analyzing the data, we can conclude that the floating object would be almost standing in one place, no matter how strong the waves are or how big the disturbance is. It is because ‘the waves travel through water, but they do not carry the water with them’ – this is what I read from our Science Explorer book. The strength of the waves-their amplitude, will only affect how much our object will move up and down.

Further Inquiry:

The major causes of error can be that I used a thin pen to create a wave, and that made the wave reach the floating object hardly. Also, I think that next time I can use a bigger tub so I can easily observe only one direction of the wave-in my case, I had a disturbance from the waves reflected from the tub borders too. For this type of experiment, I could have used more objects, not just a cup. But it is important that they can float. Otherwise, this experiment wouldn’t approve good.