An area around an object that feels a force is called?

Which one of the following research methods can show cause and effect

The slope of a velocity time graph over any interval of time gives the during that interval

Agroup of students were investigating the force of gravity. they began by dropping a foam ball from a height of 3 meters into a bucket of sand. the ball hit the sand in 0.306 seconds. they dropped additional balls of approximately the same diameter, but of different masses. here is the data they collected. based on this experiment and the collected data, what would their conclusion be?