A 74 kg student starting from rest, slides down an 11.8 meter high water-slide. How fast is he going at the bottom of the slide?
Sliding down, the major force acting in the student's weight.
Therefore, gravity is what is accelerating the student.
g = 9.8 m/
Using the equation of motion
a (acceleration) = 9.8 m/
As you can see, the mass of the student is irrelevant to the question.
Think of Galileo's famous experiment!