What made it possible for some slaves to be able to buy their freedom?

In which research method does a researcher change the value of one variable to determine how the change affects another variable? a. experiment b. observational research c. survey d. case study

When something is moving, it is in motion. pressing the gas pedal in a car will put the car in motion. two important properties of motion are speed and direction. speed is how fast an object is moving. tony and tanya both run for the same amount of time, in the same direction. tanya runs much further than tony in that time. how does tony's speed compare to tanya's speed? a) their speed is equal. b) tony is slower than tanya. c) tony is faster than tanya. d) without a stopwatch, you can't say for certain.

Agraduate student wants to examine the effect of print media versus televised media on individuals’ position on several social issues. the superintendent of a local work release facility, a family friend, will allow the graduate student access to the prison population to her quickly accrue subjects. the student’s irb should: approve this project since the risk appears to be no > minimal. not approve this project because the prisoners are merely a population of convenience for the student. approve this project since the superintendent is the ultimate authority on what happens in his facility. approve this project but submit it for federal review.