Denote the speeds of block at point a and a ′ (the same point for different two cases) to be va and va′ respectively. What is the ratio of the speeds va va′ ?.

When you look at the data about all of the children in your setting, you can learn a. about child development. b. how well each individual child is performing. c. what outside factors you need to change. d. how effective your instruction and environment are.