Obviously you bust out your university physics book and work through the equations with them! There is nothing my 9 year old loves more than doing derivatives!

Obviously you bust out your university physics book and work through the equations with them! There is nothing my 9 year old loves more than doing derivatives! We didn’t even teach her the equations for velocity or distance, we derived them starting from Jerk and integrated our way up the food chain. And none of that linear single dimension nonsense either, kiddo learned in both 3D and polar coordinates from day one; with friction too because like spherical cows, friction-free is a lie. Teaching grade schoolers single-dimension, frictionless physics really messes them up once they get into grad school and start doing real math.