1. Investigation 1 activity
And you

2. Aristotle said: Heavier objects fall faster than lighter objects
Aristotle was good at framing an argument, and had a solid reputation – so everyone said “Aristotle is so smart, so he must be right!
Until Galileo noticed that if Aristotle is correct…. we have a dilemma…

3. Galileo's line of logic:
If Aristotle is correct - and I drop an anvil and a hammer at the same time – then the anvil will fall faster…

4. SO
If Aristotle is correct – and I tie a hammer to an anvil, then the hammer (that falls slower) should slow the anvil down (like a parachute) and the hammer/anvil complex will fall slower than a lone anvil.

5. AND
If Aristotle is correct – and I tie a hammer to an anvil, then the combined mass of the hammer and anvil is greater than the anvil alone – so it is also true that the hammer/anvil complex should fall faster than the anvil alone.

6. The hammer/anvil complex can not fall faster – and slower – at the same time, so we have been led astray by the logic of Aristotle!
So what falls faster? Heavier objects, lighter objects, or do they fall at the same rate (when you control the variable of wind resistance)???
What we need is evidence based on observations and measures rather than an argument!

7. Design of investigation
Drop 2 anvils… no I only have one anvil so we can not do that!
Drop 2 balls (that are about the same size) with different masses from the top of the school – at the same instant.
Observe/record which one lands first…
Also measure the time interval of falling, and the height of the drop – we will use this data later.

8. What are we going to do????
You will go outside to make observations and measures (gather evidence)
Take video clips of the falling objects with your cellphone
Timed measures of the objects as they fall with your cellphone (3 trials)
Measure the height of the drop (3 measures)
Write down your measures of time and distance (3 people record the measures to minimize recording errors).

9. STOP HERE AND CONDUCT INVESTIGATION

10. WHAT CAN YOU CONCLUDE BASED ON YOUR OBSERVATIONS??????????????????????

11. Please make a data table in your notebook with the following headings
Time of drop (s) Height of drop (m)
__________________________________________________________
Trial 1
Trial 2
Trial 3
Average
Uncertainty

12. Uncertainty based on the average deviation from the mean
Multiple measures (of the same thing) can result in slightly different results
In this case, calculate the mean measure
Then sum all the absolute value of the deviations from that mean
Divide by the number of measures
Example: 1.50g, 1.60g, 1.70g
mean = 1.60g
deviations = .10, .00, sum of deviations = .20 / by 3 = .07
Therefore: /- .07g