Ticker Timer Lab
Introduction: Timers can mark a paper tape fast enough to make a very detailed record of the motion of a small object. Simple ticker timers have a vibrating arm which makes a series of dots on the paper tape as it is pulled through the timer. Most timers make 60 dots each second. We will measure every sixth dot, giving a record of the object’s position every 0.1 s. If the object started from rest, the first few dots on the tape are often too crowded together to count so measurements of position and time are usually started from the first clear single dot.
Purpose: The purpose of this lab is to use ticker timers to observe and analyze motion. You will analyze motion using a uniform motion car and a Hall’s car. You do NOT have to pass in a formal lab report. You only have to create the data table, make the graphs, and answer the lab questions below.
Procedure:
Part One:
1. Get a uniform motion car. Make sure the car moves forward properly, on its own.
2. Place a circular piece of carbon paper face down on the screw.
3. Then, get a piece of paper approximately one metre long.
4. Thread the paper through the slots and under the carbon paper.
5. Using scotch tape, attach the other end of the paper to the top of the car.
6. Turn on the timer.
7. Turn on the car and allow it to move until the paper is pulled through the timer device.
8. Make sure you get a nice set of data. If not, you must do it again! Verify with your teacher if the data is good or should be redone.
Part Two:
1. Get a Hall’s car.
2. Place a 1 kg weight inside the car.
3. Set up a ramp using the timer box and piece of wood, and place a backpack at the end of the ramp.
4. Place the same circular piece of carbon paper face down on the screw.
5. Then, get a new piece of paper approximately one metre long.
6. Thread the paper through the slots and under the carbon paper.
7. Using scotch tape, attach the other end of the paper to the top of the car.
8. Turn on the timer.
9. Drop the car down the ramp.
10. Make sure you get a nice set of data. If not, you must do it again! Verify with your teacher if the data is good or should be redone.
How to read your ticker timer tape:
· Every 6 dots represent a time interval of 0.1 seconds. Place a line through the first clear dot you can see. Count off six dots and place another line on the tape. Keep doing this until you get to the end of the tape.
· To measure the motion, line a ruler up with your tape starting at the first line you made. Begin from this 0 each time and measure the position of the vehicle for each time interval.
Observations:
Make the data table below on a sheet of looseleaf for both your Hall’s car AND your uniform car so that you have two separate tables. Remember, you mark every sixth dot on your ticker tape and then measure from your starting position (“0 cm”) with your collected and calculated data. (value: 16 pts)
Time (s) / Displacement (cm) / Velocity (cm)0.0
0.1
0.2
.
. / .
. / .
.
2.8
2.9
3.0
Analysis:
1. Create a displacement-time graph of your uniform motion car. This graph must have a title, labeled axis with correct units, a proper scale, and all of the points plotted. Then, connect the points with a smooth line. HINT: go up by 0.1 for each line on your x-axis (time). (value: 5 pts)
2. Create a displacement-time graph of your hall’s car. This graph must have a title, labeled axis with correct units, a proper scale, and all of the points plotted. Then, connect the points with a smooth line. HINT: go up by 0.1 for each line on your x-axis (time). (value: 5 pts)
Answer the following questions: (value: 11 pts)
3. Look at the position-time graph you created for the uniform motion car.
a. What does the slope of this graph represent? (value: 1 pt)
______
b. Does this graph show constant/uniform or changing motion? Explain. (value: 2 pts)
______
______
c. Does this graph show motion in the positive or negative direction? Explain. (value: 2 pts)
______
4. Look at the position-time graph you created for the hall’s car.
a. Does this graph show constant/uniform or changing motion? Explain. (value: 2 pts)
______
______
b. Does this graph show motion in the positive or negative direction? Explain. (value: 2 pts)
______
5. a. If the car had shown negative acceleration, explain what would this mean? (value: 1 pt)
______
______
b. Describe how negative acceleration would look on the ticker timer tape? (value: 1 pt)
______
______