1. Investigation 2 Review
3rd Grade

2. Describe which direction the wheel and axle systems will move in.
This system will move in a straight line. The axle is in the middle and both wheels are the same size.

3. Describe which direction the wheel and axle systems will move in.
This system will move in curved path. The axle is in the middle and the wheels are the different sizes.

4. Describe which direction the wheel and axle systems will move in.
This system will move in a zig-zag path. The axle is not in the middle which leaves it unbalanced.

5. What happens to an object when forces are balanced?
The object will stay in one place. There will be no motion.

6. What happens to an object when forces are unbalanced?
The object will move. There will be a change in motion.

7. Describe what we did to make a stable top. What did it look like
Describe what we did to make a stable top. What did it look like? Why did it work?
Stable tops have the disks at the bottom of the shaft. This keeps the weight at the bottom.

8. Think of a wheel and axle system we made
Think of a wheel and axle system we made. What determines the direction the wheel and axle system will move?
The size of the wheels.

9. What do we do to make a twirly bird spin faster?
Cutting the wings shorter or adding a paper clip.
Short wings = less air resistance
Extra paper clip = more weight to pull the twirly bird down quicker

10. When we are flying our twirly birds, when are the balanced
When we are flying our twirly birds, when are the balanced? When are they unbalanced?
They are balanced when they are in our hands – no motion is happening!
They are unbalanced when they are flying – there is a change in motion!

11. What forces are working on a twirly bird while it is spinning through the air?
Gravity pulls the twirly bird down.

12. Use the word bank to complete the following sentences so they describe a cause-and-effect relationship.
short
• If you make the wings of a twirly bird ___________, the twirly bird will spin ______________________.
• If you put_________________________ wheels on a wheel-and-axle system, the system will roll ____________________.
• If you place a cup on a ramp, it rolls __________________________________ because the ends have ____________________________________________.
faster
the same sized
straight
in a curved path
wheels of different sizes