GeoGebra

29 February

Two Body Problems in Dynamics

Seng Kwang Tan 03 Dynamics, GeoGebra 0 Comments

Problems involving two bodies moving together usually involve asking for the magnitude of the force between the two.

For example:

A 1.0 kg and a 2.0 kg box are touching each other. A 12 N horizontal force is applied to the 2.0 kg box in order to accelerate both boxes across the floor. Ignoring friction, determine:

(a) the acceleration of the boxes, and

(b) the force acting between the boxes.

To solve for (b) requires an understanding that the free-body diagram of the 1.0 kg box can be considered independently as only the force acting between the two boxes contributes to its acceleration since it is the only force acting on it in the horizontal direction.

This interactive app allows for students to visualise the forces acting on the boxes separately as well as a single system.

The codes for embedding into SLS:

<iframe scrolling="no" title="Two Mass Problem" src="https://www.geogebra.org/material/iframe/id/fh5pwc37/width/638/height/478/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="638px" height="478px" style="border:0px;"> </iframe>

08 February

Template for Creating GeoGebra Animations

Seng Kwang Tan GeoGebra, Simulations, Teaching Resources 0 Comments

In an introductory sharing for the use of GeoGebra to my colleagues, I have prepared a simple template for them to try their hands at animations of points and other elements.

You can try the same too. Create a moving point by typing into the Input field (5,5*sin(time)) so that you get a point at x = 5 that oscillates between 5 and -5 in the vertical direction.

28 January

Relationship between displacement-time and velocity-time graphs

Seng Kwang Tan 02 Kinematics, GeoGebra, IP3 02 Kinematics, Simulations 0 Comments

Through this GeoGebra app, students can observe how the gradient of the displacement-time graph gives the instantaneous velocity and how the area under the velocity-time graph gives the change in displacement.

In the GeoGebra app below, you will see a displacement-time graph on the left and its corresponding velocity-time graph on the right. These graphs will be referring to the same motion occuring in a straight line. Instructions

  1. Click “Play” and observe the values of displacement and velocity change in each graph over time.
  2. Note the relationship between the gradient in the displacement-time graph and the value of velocity.
  3. Note the relationship between the area under the velocity-time graph and the value of displacement.
26 December

Work Done Simulation

Seng Kwang Tan 05 Work, Energy and Power, GeoGebra, IP3 06 Work, Energy and Power 0 Comments

This GeoGebra app allows users to change the magnitude and direction of the force acting on an object, as well as the initial velocity.

The change in kinetic energy is calculated along with the work done in the direction of the force.

This demonstrates a very important concept in Physics known as the Work-Energy Theorem, where the net work done on a particle equals to its change in kinetic energy.

08 December

Uniform vertical circular motion

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

The following GeoGebra app simulates the force vectors on an object in uniform vertical circular motion.

A real world example of this would be the forces acting on a cabin in a ferris wheel.

<iframe scrolling="no" title="Vertical Uniform Circular Motion " src="https://www.geogebra.org/material/iframe/id/t5jstqsm/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>