Here you can see my dad partaking in my physics learning.  He is in the process of rolling a tennis ball down a slope.  I have explained to him that in contrast to walking at a constant rate, when you roll a ball down a slope it's velocity is actually increasing.  This is because of gravity, which pulls on everything at a rate of 9.8 m/s/s.  My father now understands that because of this acceleration, a graph of the position vs. time of the ball would show an exponential curve.  I have also explained to him how, using the equations we learned in class, we can find distance, acceleration, and time with a few givens.