Lever practice

1. What IS a center of mass (CM)?

2. Is the CM necessarily ON the body? If not, why not? Where else could it be?

3. What does it mean for something to be stable? That is, what does it say about the location of the CM?

4. Why is a tall SUV more likely to tip over rounding a curve than, say, a low-riding sports car?

5. Consider a see-saw, initially balanced. A 100-lb person sits 2 feet to the right of the fulcrum. Where could a 150-lb person sit to keep the see-saw balanced?

6. Consider a cantilever - a 8-ft long board with a fulcrum 2-ft from the left end. There is a 40-lb child sitting 1-ft to the left of the fulcrum, balancing the board. Considering that the CM of the board is located exactly in the middle of the board, what is the weight of the board? Draw this out first.

7. Review some of the CM demonstrations done in class - consider what makes one thing stable or unstable.