Tag Archive | diode

Day 141: How Big is the Sun?


College-Prep Physics: It was sunny out today! So we poked a hole in the side of a copy paper box to make a pinhole camera. Aimed our cameras at the sun and measured the resulting image in order to determine the true size of the sun. The copy paper box worked beautifully: the sides with the hole and the screen are always parallel; it’s easy to aim the camera directly at the sun — lay box on ground and lift up/turn until box shadow is square; for the size of the box, the image of the sun is exactly 1/2 cm across (so it fits perfectly within 1/2 cm graph paper). We didn’t do anything fancy with foil like I’ve seen for other pinhole cameras on the internet. Should we have? Why?


Conceptual Physics: Students finished the diode circuit simulation activity from yesterday. One group came up with a possible bike generator circuit that will charge the battery and light the bulb while pedaling, and will also use the battery to light the bulb when the pedaling stops.

Day 140: Gravitational Force vs. Distance

College-Prep Physics: We were supposed to go out and explore pinhole cameras, but it was cloudy. So today we explored gravitational force with a sim from The Physics Classroom: http://bit.ly/gravitysim. Students are doing a similar analysis like they did with light intensity a few days ago. Handout here: ACTIVITY Universal Gravitation 2013

Conceptual Physics: I found a great circuit simulation which has diodes (PhET doesn’t have diodes): http://bit.ly/acdclab. Students explored diodes and AC circuits with this today. Hopefully it will allow them to understand diodes better and be able to come up with a draft of their modified bike light generator circuit. Handout here: DiodeCircuitSimLab2013

Day 137: What Is A Diode?


Conceptual Physics: Here a bike light generator is connected to a voltage probe in Logger Pro. The red graph shows what we saw yesterday — the voltage cycles positive and negative (AC). The blue graph shows what happens when a diode is added to the circuit. Diodes will be important later when we use the bike generator as a battery charger.

College-Prep Physics: Based on students’ work to the M&M (light collection) lab and the properties of light activity from prior days, I decided to do a review of mathematical relationships. The handout is here: MATH RELATIONSHIPS