Have you seen the famous “dippy bird,” a particularly favorite toy of Homer Simpson? Why does it work? Why does it need water? What powers it? Would it go on forever? What exactly does the tail add? This experiment will investigate why this unusual bird drinks.
Student Guide
Drinking Bird Races
An exploration of using metal to melt chocolate
How do different metals conduct heat?
This resource was originally published in PhysicsQuest 2011: Spectra Heats Up!
How do different metals conduct heat?
- 2x Drinking Birds
- Alcohol pads
- Large plastic bag
- Cup of water
- Stopwatch
Intro
Before the experiment
What does “evaporation” mean?
How does it feel when water or sweat evaporates from your skin? What about rubbing alcohol? How might you use rubbing alcohol?
What types of things undergo “periodic motion?” How would you describe this kind of motion?
Setting Up
Take both birds out of their boxes and set them side by side. Label them “alcohol” and “water.” Or, if you want to, feel free to name them. Alfred and Walter have a nice ring to them.
Slide the bird in the metal cuff till it’s in the middle of the bird. This will allow the bird to balance correctly.
Open the bag and make sure it can fit over the drinking bird without touching it or getting in the way of its “drinking.”
Place a cup of room temperature water in front of the “water” bird.
During the experiment
Collecting data
Give your “water” bird a tap on the back of the head and draw or write what happens.
Take the bird marked “water” and dip his or her head in the water, getting the beak and head a bit wet. Let go and watch what happens.
As the bird moves, it dips all the way down to “drink”, pops back up, rocks back and forth for a bit till it dips all the way down again to “drink.” We’re going to measure the period of the bird’s drinking by measuring the time between “sips.” A ‘sip’ is when the bird is completely horizontal.
Let the bird “drink” a few times then start the timer when it is taking a “sip.” Let the bird “sip” 5 times and write down the time. To find the period of the birds “drinking” take the time for 5 “sips” and divide by 5. Time for 5 “sips” of water _____ Period of “drinking” water _____
Let your first bird continue drinking and put it next to the bird labeled “alcohol.”
Take two alcohol pads and soak the head of the bird marked “alcohol” with the rubbing alcohol.
Repeat step 3 and measure the period of the bird’s drinking.
- Time for 5 “sips” of water _____
- Period of “drinking” water _____
Again take the bird marked “alcohol” and soak wrap two alcohol pads around its head till it is soaked.
Allow the bird to “drink” a few times.
Place the plastic bag over the bird making sure not to touch any part of the bird (Fig. 2).
Record what happens.
Remove the bag and record what happens.
Repeat steps 1-4 two more times.
Analyzing data
What were your results?
- What happened when the bird’s head got wet?
What was the period for the bird dunked in water? How was this different from the period of the bird dunked in alcohol?
What happened when the bag was placed over the bird? Were you surprised? Why do you think the bag affected the bird?
Why do you think the bird dipped in alcohol had a different period than the bird dipped in water?
Conclusion
Why do you think the bird dipped in alcohol had a different period than the bird dipped in water?
Thinking about the differences between alcohol and water as well as what happens when you place the bag over the bird’s head, what do you think is causing the bird to “drink?”