# Homework Help: Stupid SHM questionshelp

1. May 17, 2005

### bjon-07

Hi all, I have been studying for my physics final which is tomorrow for the past 9 hours..my brain hurts.....sorry if this question is dumb

I keep getting

f=freq
T=period

mixed

what is the difference between the two again in the physical sense (i.e. would the motion of pistons in a car be f or T)

I know that T=1/f

2. May 17, 2005

### Staff: Mentor

Period and frequency are two sides of the same coin. They both can be used to describe the same motion. To keep them straight, think of the units they are measured in. Period is the time for one complete cycle of the SHM (think period of time); thus it is measured in seconds (or any other unit of time). Frequency is the rate at which the SHM repeats itself in cycles per second; thus it is measured in cycles/second or just 1/sec. You know how to convert from one to the other.

I hope this helps a little.

3. May 17, 2005

### z-component

The motion of pistons in a car could use both of these, however, the motion of the pistons themselves are just Simple Harmonic Motion. They can be measured in period and frequency, if that's what you mean. The frequency of the pistons would be how many times they cycle per a given time and the period would be how long it takes for them to do just one cycle. Hope this helps.

4. May 17, 2005

### whozum

Period: Think of a period of time when something is happening. Period in SHM is the time for oen complete oscillation, aka the time it takes for the motion to finish a cycle and start repeating.

Frequency: How frequently is it happening? How many times per second?

5. May 17, 2005

### bjon-07

Thanks for the help guys. I can't believe I forgot that ><. Well I got to get back to work. Thanks again for the help, this site rocks!!!!