Recent content by Parsa

I teach in a public school. I'm still using 40 year old equipment. I haven't had curriculum-cycle funds in the 23 years at my school. Generally we get about $800 to spend in a year. Often that works out to about $4 a year per student. One single lab apparatus often costs several hundred, so...

An electromagnet vibrates a metal strip, usually at the mains frequency (50 or 60 Hz). The metal hits a carbon paper circle with ticker tape under it. It makes a mark every 1/50 th or 1/60 th of a second. They're used to find the speed or acceleration of an object pulling the tape through the...

Hi, I'm new to the forum... I just modified some ticker timers to serve as standing wave generators for my class. It got me wondering when ticker timers were first used to do physics motion experiments. I'm assuming it was from the time they had telegraphy, so maybe as early as the later 19th...