Logic Flow For 3-Day Investigation Activity

Activity: Touchdown, Safely!

Outline of Daily Progression

• Day 1 - Free-Fall Lab
• Day 2 - Discussion of what the outcomes of the lab mean, and introducing the Egg Drop Activity. (Ideally this would be a Friday so students would have the weekend to build their contraptions
• Day 3 - Test the students contraptions.

Logic Flow:

• Gravity affects all objects.
• We feel the gravitational acceleration cause by Earth the most.
• Gravity on Earth is a form of uniform acceleration toward the center of the Earth.
• Therefore, it acts on all objects that are near Earth's surface equally, pulling them toward the center of Earth. 
•  In a vacuum, gravity causes any two objects to fall at the same rate, regardless of mass.
• Earth's Atmosphere is not a vacuum.
• Air causes friction as you move through it.
• The amount of friction, depends on surface area.
• Therefore, things of different sizes will be affected more, or less by the air resistance.
• We can use air resistance to change the velocity of something as it moves through air.
• Changing velocity of something, changes the length of time it will fall.
• Therefore changing surface area, we can affect time and velocity of a falling object.
• Gravitational Potential energy = mass x gravitational acceleration x height
• kinetic energy = 1/2 x mass x velocity squared
• Force x change in time = mass x change in velocity
• Therefore, we can change the amount of force an object hits the ground with if we change the kinetic energy of the falling object.
• Therefore, changing the velocity an object falls with will change the force it hits the ground with.
• We have 1 egg.
• We have 5 sheets of paper and 1 meter of string -or- we have 100 straws and 1.5 meters of masking tape -or- 3 sheets of paper, 20 straws, 3/4 meter of string, and 1/10 meter of tape
• An egg will crack if it hits the ground with to much force.
• We don't want scrambled eggs at school.
• We are going to drop the eggs from a height of 15.25 meters (50 ft.)
• Therefore, we will need to build a contraption out of the materials provided, that will keep the egg from breaking after it falls 15.25 meters.

Some of the stuff in this logic flow will be brought in from class discussions that occurred prior to working on the Free Fall Lab, but in order to put together a beneficial understanding of the whole activity it was important to put in to the logic flow.