A student is skateboarding down the street. Which of the following would be a good reference point to determine her speed? Explain your reasoning. a. Moving bus
b. Tree
c. Flying bird
d. Parked Car

Consider a cube that has sides of length l. now consider putting the largest sphere you can inside this cube without any point on the sphere lying outside of the cube. the volume ratio -volume of the sphere/ volume of the cube is 1. 5.2 × 10−1 2. 3.8 × 10−1 3. 1.9 4. 2.5 × 10−1 5. 3.8