May you please help me on this one.

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?

What is a person called when they are on your side and supports you

The belmont principle of beneficence requires that: a. subjects derive individual benefit from study participation.b. potential benefits justify the risks of harm.c. the study makes a significant contribution to generalizable knowledge.d. risks are managed so that they are no > minimal.