# Quick question on find freq/amp

1. Feb 18, 2005

### bjon-07

Hi all, I am doing my physics lab write up. We used a Behr Free-Fall Apparatus to find g. The apparatus "zaped" a piece of paper ever 1/60 of second. What is the Amp of current running through the machine. thanks a ton.

2. Feb 18, 2005

### HallsofIvy

Staff Emeritus
Whether you are using "Amp" to mean "amplitude" or "amperes" (which I suspect would be the same thing here), neither depends on the frequency.

3. Feb 18, 2005

### Andrew Mason

What does it matter? You aren't interested in the composition of the metal in the stand either. Part of physics is knowing what is relevant and what is not - so if you are worrying about the current required to make the spark your teacher might infer that you are missing the point of the experiment. All you are interested in is the frequency of the spark and the distances between the spark burn marks on the tape.

AM

4. Feb 18, 2005

### bjon-07

Sorry for the confusion but why I want to find is clylic rate at which the electricity is alternating. This in theory should well tell me how many times per second the deviced will zap the target. I know its not nessarcy to find g, but I would like to be very througll in my lab reprt.

5. Feb 18, 2005

### Andrew Mason

The spark rate is not necessarily the same as the frequency of the alternating current. The spark is presumably caused by an induction coil with a switch making and breaking contact 60 times/second (like the ignition system on a car). Check the specification for the equipment to find out the number of sparks per second (to verify that it is 60).

AM