Date Due: 2013.09.23____
Name: Lily Li____
Class: A__
Teacher: ___Mrs Slater___
Purpose:
To determine the period and the frequency of a ticker timer.
Materials/Apparatus:
One ticker timer One carbon paper disc
One 1.5+ meter tape One test tape
One stop-watch
Theory:
The recording timer is a device that helps you study motion, it is a simple electric device plugged into mains power, with a stylus that vibrates up and down. The stylus hits a tape that can be drawn through leads, and presses it onto the carbon disc below. This leaves a dot on the tape for every hit. The power source ensures that the vibration of the stylus will be regular. The period(T) of the timer it takes for the stylus to move all the way down and then up-one complete cycle. The frequency(f) of the timer is how many times the stylus goes through a cycle in a second. So the frequency is the reciprocal of the period, and the period is the reciprocal of the frequency. We will calculate the frequency using formula Frequency(f)=number of dots/ time, and then calculate the period using formula Period(T)= per unit time/ frequency.
Procedure:
1. Follow instructions and assemble the apparatus.
1. Put a carbon paper disc which is carbon-side-up on the fix shaft between the gates.
2. Place a short strip of timer tape in the recording timer over the paper disc.
3. Make sure the tape is threaded through the gates and is free of snags.
4. Turn the timer on and pull the strip through the gates.
5. Make sure you are getting dots on the underside of the tape.
6. Use the test tape to decide on the best speed to pull the tape, so that the dots are easy to read.
7. Place a +1.5 meter piece of tape in the timer.
8. Pull the tape through a gentle, constant motion with one hand.
9. As you pull, operate the stop-watch with the other hand. The time should be close to 3