Please help me with 4 questions

Mr. mann's science students were experimenting with speed. they set up a 1 meter (100 cm) track. the students used balls instead of cars. the balls were different sizes and made of different materials. four at a time, students rolled balls around the track to see which had the fastest and slowest speeds. some of their data are shown in the table. which ball will take the longest to complete one lap around the track?

Which best expresses the radical republican philosophy of reconstruction? a. the confederate states were conquered territories that should be ruled by military governors. b. the southern states actually never left the union. c. if ten percent of the voters of a state that had seceded took an oath of allegiance to the union, then it should be readmitted as a state.

Persons who have not yet attained the legal age of consent under the applicable laws in the jurisdiction in which the research was approved. persons who are under 18 years of age. persons who have not yet attained the legal age of consent under the applicable laws in the jurisdiction in which the research will be conducted. persons who are under 21 years of age.