A-level Topics

06 December

Vertical Non-Uniform Circular Motion

Seng Kwang Tan 06 Motion in a Circle, GeoGebra, Simulations 0 Comments

This is a simulation that shows the vectors of forces acting on an object rolling in a vertical loop, assuming negligible friction.

To complete the loop, the initial velocity must be sufficiently high so that contact between the object and the track is maintained. When the contact force between the object and its looping track no longer exists, the object will drop from the loop.

The following code is for embedding in SLS.

<iframe scrolling="no" title="Vertical non-uniform circular motion" src="https://www.geogebra.org/material/iframe/id/ny3jhhsp/width/640/height/480/border/888888/sfsb/true/smb/false/stb/false/stbh/false/ai/false/asb/false/sri/true/rc/false/ld/false/sdz/false/ctl/false" width="640px" height="480px" style="border:0px;"> </iframe>
01 December

Hydrostatic Pressure and Upthrust

Seng Kwang Tan 04 Forces, GeoGebra, IP Topics, Simulations 0 Comments

This app is used to demonstrate how a spherical object with a finite volume immersed in a fluid experiences an upthrust due to the differences in pressure around it.

Given that the centre of mass remains in the same position within the fluid, as the radius increases, the pressure due to the fluid above the object decreases while the pressure below increases. This is because hydrostatic pressure at a point is proportional to the height of the fluid above it.

It can also be used to show that when the volume becomes infinitesimal, the pressure acting in all directions is equal.

The following codes can be used to embed this into SLS.

<iframe scrolling="no" title="Hydrostatic Pressure and Upthrust" src="https://www.geogebra.org/material/iframe/id/xxeyzkqq/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>
30 October

Noise-cancelling AirPod Pro

Seng Kwang Tan 12 Superposition 0 Comments

The recently launched Apple AirPod Pro presents a wonderful opportunity to relate an A-level concept to a real-world example – how noise-cancelling earphones work.

Apple’s website explained it in layman terms that seem to make sense. Let your students attempt to do a better job of explaining how destructive interference of waves is applied.

I probably won’t spend SGD379 on it though.

02 July

Phase Difference GeoGebra Apps

Seng Kwang Tan 11 Wave Motion, 12 Superposition, GeoGebra 0 Comments

I created a series of GeoGebra apps for the JC topics of Waves and Superposition, mainly on the concept of Phase Difference. The sizes of these GeoGebra apps are optimised for embedding into SLS. When I have time, I will create detailed instructions on how to create such apps. Meanwhile, feel free to use them.

Instructions on how to embed the apps into SLS can be found in the SLS user guide.

Phase difference between two particles on a progressive wave. Move the particles along the wave to see the value.

Phase difference between two particles on a stationary wave. Move the particles along the wave to observe how their velocities are different or similar.

Observe velocity vectors of multiple particles on a progressive wave.