# Day 30: The Falling Moon [Calculus Without Calculus]

Yesterday’s lab in AP Physics C was a nice lead-in to today’s question:

The moon stops moving and begins falling towards Earth. Determine….

1. Work done by Earth’s gravity
2. Moon’s change in kinetic energy
3. Moon’s speed when it hits Earth

After realizing that the force wasn’t constant, we decided we could split the distance between the Earth and Moon into chunks and estimate the work done for each chunk. I lead the class through a quick-and-dirty GlowScript program that could do this for us. I prettied it up to share with you here:

(It’s an interactive Trinket! Change value of N to see how the estimated values for work and impact speed change.)

I need to improve how I incorporate these programming “lead-throughs” in class. I’m thinking maybe a sheet with prompts along the way. They wouldn’t be writing the program from scratch, but the prompts would ask them for key lines of code that I would add to the program I was writing. (I’m always torn between the time needed for them to code on their own vs. the time I can do it more efficiently as a demonstration to illustrate a concept.)

And now thinking about it, it isn’t really the code syntax that’s important, but how to break down the problem into the steps of what we want the code to do for us (split distance into chunks, calculate Fg at a chunk, calculate dW at a chunk, add up the dWs, etc.). So now I think a sheet with question prompts for code is counterproductive. Maybe have them write pseudocode on whiteboards which outline the general process instead?

(Sorry for the stream of conciousness rambling.)