6. A girl pushes her little brother on his sled with a force of 300 N for 750 m. a. How much work is this?
b. How much energy is used?
c. How much power does she use if it takes her 25s?
d. How much power does she use if she runs and complete the 750m in 10s?

In 1859, charles darwin published the first edition of on the origin of species, which explained his observations of various groups of animals that showed great similarities but minor differences. darwin concluded that if a population of one species separates into two different populations that live in separate locations, then over the course of many generations the different populations can develop into different species. this idea predicted many future biological findings and became the basis of modern biology. darwin’s explanation for why different species exist is best described as a(n) law. theory. inquiry. hypothesis.