LAB 1: INTRODUCTION TO IOLAB AND SOFTWARE

OVERVIEW

The IOLab is a versatile tool that can measure a variety of physical phenomena including the following:

• Position
• Velocity
• Acceleration
• Force
• Rotation
• Magnetic Field
• Atmospheric Pressure
• Temperature
• Sound
• Light Intensity
• Electricity (voltage, current, resistance)

The software associated with the IOLab has numerous capabilities including the following:

• Graph of a variable versus time
• Zoom
• Average
• Standard deviation
• Slope
• Area under curve

Don’t worry if the meaning of all of these terms is not clear. The goal of this lab is to learn to use the IOLab and its software, not to understand the physical meaning of the data.

INVESTIGATION 1: MEASURING AND GRAPHING

Let's practice using the IOLab and software to collect data and make graphs.

Activity 1-1: Wheel

Velocity is a measure of how rapidly (and in what direction) something is moving. You will move your IOLab and obtain a graph of its velocity. Complete the following steps:

1. Insert the dongle (the object that looks like a flash drive) into a USB port on your computer.
2. Turn on your IOLab by pressing and holding the right button .
3. Place the IOLab on a flat, smooth surface such as a table so that the wheels are down.
4. Note that the graph to the right is titled velocity.
5. Click the Record button and move the IOLab to the right in the direction that the y-axis points (the direction from the double wheels toward the single wheel). Than move it back. The vertical axis of the graph records the "velocity” while the horizontal axis records time.
6. Click Stop.

Question 1-1: What is the sign of the velocity when you move the IOLab in the direction of +y?

INVESTIGATION 2: MEASURING AND GRAPHING

You will practice using the IOLab and software to collect more data and make more graphs.

Activity 2-1: Graphing Angular Velocity

Angular velocity is a measure of how rapidly (and in what direction) something is spinning. You will spin your IOLab and obtain a graph of its angular velocity. Complete the following steps:

1. Place the IOLab on a flat surface such as a table so that the wheels are up
2. Ensure the graph to the right is titled Gyroscope.
3. Uncheck the boxes next to ωx and ωy.
4. Click the Record button and spin the IOLab keeping it flat on the table. Try spinning clockwise, counterclockwise, and with changing speed. The vertical axis of the graph records the “angular velocity” while the horizontal axis records time.
5. Click Stop.

Question 2-1: What is the sign of the angular velocity when you spin the IOLab clockwise?

INVESTIGATION 3: GRAPH MANIPULATION AND STATISTICS

The IOLab software can do much more than simply make a static graph. You can also manipulate the graph and generate useful statistics. For this investigation you will need the following equipment:

• IOLab
• Computer and IOLab software
• Smooth ramp or other level surface
• Blocks or textbooks to elevate one end of the ramp such that the ramp makes an angle of 15-20° with the table
• Protractor

Activity 3-1: Using a Velocity Graph to Calculate other Quantities

1. Note that the title of the graph to the right is Wheel-Velocity
2. Raise one end of the ramp with blocks or textbooks so that the ramp is roughly 15-20° from horizontal. Use a protractor!
3. Hold the IOLab at the top of the ramp with the wheels on the ramp and the y axis pointing down the ramp
4. Click Record.
5. Wait one second.
6. Release the IOLab and catch it at the bottom of the ramp.
7. Click Stop.

You should now have a graph of velocity vs. time, but it likely has lots of useless empty space. This graph can be made more useful by zooming in on the relevant portion. This graph can also be used to determine displacement, average velocity, maximum velocity, and acceleration.

1. Click on the magnifying glass on the top of the page.
2. Click and drag the cursor on the wanted section of the graph
3. Click on the bar graph icon to the left of the magnifying glass at the top of the page.
4. Click and drag across the section of the graph with a positive slope.

There are several useful statistics displayed at the top of the graph axes:

1. The symbol Δt represents the time interval selected. In this case, it is the time it took the IOLab to roll down the ramp.
2. The Greek letter μ(mu) is the mean or average of the data. In this case, this is the average velocity.
3. The symbol a is the area under the graph shown in green. In this case, this is the displacement of the IOLab (roughly the length of the ramp).
4. The symbol s represents the slope of the graph. In this case, this is the acceleration of the IOLab.

Question 3-1: For your run, what were the time interval, average velocity, displacement, and acceleration of the IOLab as it rolled down the ramp?

Time Interval: Average Velocity: Displacement: Acceleration:

Move the cursor around the graph to obtain velocity data at particular instants in time. These should appear just below the word Velocity on the graph.

Question 3-2: What was the maximum velocity of the IOLab during your run?
Max Velocity:

Activity 3-2: Calibrating the IOLab

Similar to the scales you find in grocery stores, you can measure the weight of something by hanging it from a hook attached to one end of the IOLab.

1. Screw in the hook.
2. Calibrate the force sensor by clicking on the icon: and selecting Calibration and then Force. Place the IOLab on a table as follows.
   
   
   
3. Click on the Next button.
4. Suspend the IOLab from the hook as indicated in the following figure.
   
   
   
   
5. Click on Next button. And you are done.
6. Now you will be able to weigh something including the IOLab.

Activity 3-3: Measuring the Weight of the IOLab

After calibration you can measure the weight of something, including the IOLab itself!

1. Now you can weigh the IOLab. Click record.
2. Next hang the IOLab from the hook. You will see that the force measured is about 2 N. You just measured the weight of the IOLab. If you do not know what this “N” stands for (newtons) do not worry. 2 N is about equal to 0.44 lbs. We will cover this unit later in this course.
3. Now hold the IOLab with the hook pointing down and hang something from it. You are using the IOLab just like you would a scale in the grocery store.


Question 3-3: What object did you weigh?
What did you weigh: How much did it weigh in N? Does that seem reasonable?

Activity 3-4: Identifying Kinds of Motion

1. Set up a level smooth surface that you can easily tilt and put the IOLab on its wheels.
2. Ensure Wheel is being graphed and press Record. Tilt your surface a little bit one way. The IOLab will want to run off the surface. Stop it before it falls off. In the following you will explore this motion and describe what you did and what you observed.

Question 3-4: Did the IOLab move with a steady speed or did it's speed increase? What was happening before you tilted the surface? What happened after the IOLab was stopped? What happens if you tilt the surface the other way?

ALL DONE!

To submit your lab report online, follow the following video.

Please remember to edit the report (insert your name - and if necessary your partners), export the report and submit it on D2L.

Now do the homework associated with this lab.