1. Gravity & Air Resistance
Testing the forces of
Gravity & Air Resistance

2. What are Rotocopters?
Today, we’ll investigate gravity and air resistance using rotocopters.
When you throw them in the air, these paper toys spin as the slowly float back down to earth.

3. Building a Rotocopter CUT along SOLID LINES only!
FOLD along DOTTED LINES.
Step 1 Step Step 3

4. Gravity & Air Resistance
Question: How can we make a rotocopter fall faster? slower?
Hypothesis: I think I can make the rotocopter fall faster by ___________. I think I can make the rotocopter fall slower by _______________________.
(Hint – you can’t change gravity – so which other force can you change to speed up or slow down the rotocopter? How could you change the force?)

5. Changing your Rotocopter
The rotocopter you built will be the “control”. You will test 3 other modified rotocopters against the “control”.
How can you modify your rotocopter? (which variable will you change?)
- change the size of the rotocopter
- change the length or shape of the blades
- punch holes in the blades
- type of paper its made from
- change the angle of the blades
- other ideas???

6. Observations: Describe your 3 modified rotocopters.
Drop the rotocopters from a height of 2 meters and note which one lands first. Repeat each trial 3 times.
Trial
Which lands first?
Control vs. ____________

7. Conclusions:
Which forces are acting on the rotocopter? (Draw a picture!)
How did you make the rotocopter fall faster? (How did you change the air resistance?)
How did you make the rotocopter fall slower? (How did you change the air resistance?)
Give 2 examples of when an engineer would need to consider gravity and air resistance when designing an object/vehicle?

8. Air Resistance Review
Some objects take longer to fall – they are slowed down by FRICTION with the air called AIR RESISTANCE.
The larger the surface area, the greater the force of air resistance pushing UP.
Without air resistance, all objects would fall at the same rate…