# Day 36: Electric Power & Unbalanced Force Problems

Physical Science: Electric Power

Students plugged several different light bulbs into Kill A Watt meters to find the power used by each, then calculated how much you’d pay for the electricity to use each one for a year. This is the first year I’ve done energy before electricity with my 9th graders, so I decided to have them sketch energy bar charts for each light bulb, using thermal energy and light as the energy types. For the first time, my students had an easy time articulating in a meaningful way why the low wattage LED was just as bright as the high wattage incandescent.

Physics: Unbalanced Force Problems

Students worked on some problems that combined Newton’s 2nd Law with constant acceleration calculations. I was a little nervous, because they just got Fnet = ma yesterday and many are still mastering net force, so I wasn’t sure how they’d do with using multiple models on a single problem. However, a lot of pieces seemed to really click today. By the end of the hour, several students who’ve been struggling with constant acceleration declared today’s problems easy, including the portions where they had to do constant acceleration calculations.