# IP3 01 Measurement

## Micrometer Screw Gauge – Self-Practice GeoGebra Applet

After completing the vernier calipers applet, I simply had to do a similar one for the micrometer. However, this was a lot more complex as the thimble’s numbers are supposed to be “rotating” rather than moving linearly. A lateral movement of the thimble had to be coupled with a vertical movement of the rotating scale, with the corresponding numbers on the scale constantly changing with each new problem.

Students will need to make readings when the spindle is closed and when open to measure an object before subtracting the zero error and keying in the answer for the actual measurement. The answer will be checked for accuracy, although not for the correct number of decimal places because I have not figured out a way to programme that check yet.

To access the applet in fullscreen, go to https://www.geogebra.org/m/qedrwymk. To embed into SLS, you may use this code:

<iframe scrolling="no" title="Micrometer with zero error" src="https://www.geogebra.org/material/iframe/id/qedrwymk/width/640/height/480/border/888888/sfsb/true/smb/false/stb/false/stbh/false/ai/false/asb/false/sri/false/rc/false/ld/false/sdz/false/ctl/false" width="640px" height="480px" style="border:0px;"> </iframe>

## Vernier Calipers – Self-Practice GeoGebra Applet

The aim of this applet is to help students who just learnt about zero errors in vernier calipers to get some practice of their own. Students just have to key in their answer into the textbox and they will know if they got it correct.

To modify later: an option to give the correct answer if the student asks for it.

I have not figured out how to ensure that the input is expressed in 2 decimal places, so if any expert is able to advise, I will be glad to try it out.

To access the applet in fullscreen, go to https://www.geogebra.org/m/jybrnwgp. Meanwhile, the applet is embeddable in SLS using the following iframe code.

<iframe scrolling="no" title="Vernier calipers with zero error" src="https://www.geogebra.org/material/iframe/id/jybrnwgp/width/640/height/480/border/888888/sfsb/true/smb/false/stb/false/stbh/false/ai/false/asb/false/sri/false/rc/false/ld/false/sdz/false/ctl/false" width="640px" height="480px" style="border:0px;"> </iframe>

Credits to Abdul Latiff for the original applet which I modified to add the zero error readings.