The diagram in the computer program works correctly.Update Information...
To get the updated version, download the instal program and re-instal it. It will overwrite the old version.
Skater - the speed, displacement and acceleration data has been made more precise and given to more decimal places so the connection with average speed and distance covered per second is consistent. The freeze and air resistance buttons have been improved. A bug that happened when trying to reset while freeze was on has been fixed. A line is drawn on the acceleration graph to show exactly when the acceleration changes. All references to 'distance' have been replaced by 'displacement'.
EField - no-go areas have been introduced above, below and - for the equi-potentials - to the right of the plates so that field lines and equi-potentials can't go there. This fixes a bug that allowed incorrect lines to be plotted in those regions. Overprinting of data in the table on printouts has also been fixed.
Gravity - a new program that plots gravitational field lines for a planet with a moon and electric field lines for two point charges of different types. It is useful for comparing the shapes of gravitational and electric fields. The download package is called InstalGravity. Once installed the program comes up as Field Lines. Comments please.
Skater - on the printout, the changes in the speed that occurred when the acceleration was switched on or off did not compute. This has been corrected so that if you take the fraction of the 1 second interval that the acceleration was at its new value x the acceleration, this gives the correct change in speed.
SHM - the box underneath the moving bead gave the acceleration as - when displacement was negative and + when displacement was positive. This has now been corrected so that acceleration is positive for negative displacements and negative for positive displacements.
Triangle of Forces - the
diagram on page 39 of Advanced Physics Laboratory Book (a text
that uses these programs) should look like this.
The diagram in the computer program works correctly.
20 December 2003
Ripple - a new program that simulates the behavior of water waves in a ripple tank. It shows clearly, the reflection, refraction diffraction and interference of waves and prints out useful diagrams. I've also added the doppler effect on circular waves from a moving source. Although this does not feature in UK syllabuses you see it happening on every duck pond. These wave behaviours are often tricky to see in the ripple tank. Comments please.
Ripple - an error in the printing of the diffraction pattern of waves passing through a gap has been corrected.
Shoot - a program that simulates the motion of a football being kicked on the moon and other planets. The angle and speed of projection can be altered. This is not yet incorporated in the PhysicsLab package.
Hertz - a new program about the shape and frequency of sound waves. The waves are made by a signal generator and turned into sound by a loudspeaker. An oscilloscope shows the waves and its time-base control can be used to measure the period and frequency of the sound. A harmonic generator allows you to add a harmonic to the fundamental wave to investigate the quality of the sound.
InstalPhysicsLab - the two latest programs - Shoot and Hertz - have now been included into this instal package, making a total of 24.
Boom - a new program that simulates the forced vibration of an air column by a tuning fork. A classic experiment that demonstrates resonance, longitudinal standing waves, and gives a value for the wavelength and speed of sound. It is not included in PhysicsLab yet. Feedback please.
Hertz - a phase button has been added to the harmonic generator so that waves can be added destructively as well as constructively. Useful for demonstrating (and hearing) the superposition of sound waves.
InsalPhysicsLab - Boom, which uses resonance of air in a pipe to measure the speed of sound, is now included in this instal package. Still free for use in the name of physics teaching !
Skater - sound has been added to the rocket engines and a scream if she crashes into the wall. The readings do not now get wiped out until you start a new journey. If you already have a PhysicsLab installation, InstalSkater will overwrite the old version - go to Distance, speed and acceleration / time graphs.
Gas - a 'copy to clipboard' button has been added to the menu so that readings of pressure, volume and temperature can be pasted into spreadsheet programs such as Excel. You can then plot graphs to your own taste. This is in a response to a suggestion made by a user. Go to The ideal gas laws
5DoubleSlit - a new program showing the double-slit interference of light. The light can be shown as 'ripples' that are diffracted as they pass through the two slits and then overlap and interfere. Or as two wave streams that meet on a screen. The point where they meet can be changed to show how the phase difference between them depends on how far they have traveled. Go to The Double Slit Experiment.
InternalR - the measurement of the internal resistance of a battery has been split into two experiments. The simpler one uses an ammeter and voltmeter and gets internal resistance from a p.d. current graph. The second uses only a voltmeter but uses a more complicated graph to get the internal resistance. I arranged it like this after noticing the difficulties some of my students had with the E/V against 1/R graph. I have also sorted out some minor bugs but no doubt there are more. Please let me know.
Boom - thanks to some helpful feedback, the frequencies of some of the notes have been changed to give a proper musical (doh ray me) scale.
Shoot - some bugs have been sorted and a 'catcher' added. This adds a simple gaming option for those not particularly interested in the maths of the motion and who just want to compare the effect of the gravity of different planets on the flight of the football.
Discharge - a new program showing the discharge of a capacitor through a resistor. The resistance and sampling rate can be changed and the p.d. recorded at each time interval. Graphs can be plotted and capacitance calculated from them. The effect of the resistance of the voltmeter can be seen when using large resistors.
Gravity - a new program showing the discharge of a capacitor through a resistor. The resistance and sampling rate can be changed and the p.d. recorded at each time interval. Graphs can be plotted and capacitance calculated from them. The effect of the resistance of the voltmeter can be seen when using large resistors.
Twave this now has sliders to change the amplitude and wavelength and elastic connecting the beads to represent the force that transmits the motion. 'Deep thought' also gives an explanation of the motion of a travelling wave.