Please help me understand the answer to this one ? I feel it’s a. But I’m not sure

The coefficient of friction is a number that represents the resistance to sliding between two in contact with one another.

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?

If the textbook weighs 19.6 newtons on venus,what is the strength of gravity on venus?