Quantum And Waves

Question 1

First off in stationary waves what type of motion does it follow?

So how could we calculate accelerations etc

Answer 1

SIMPLE HARMONIC, don’t lack, remember SHM condition is acceleration proportional to displacement and periodic oscillations, it has that, so it must be SHM

Thus can calculate accelerations etc using formula

Question 2

Why does creating a standard wave in a tube with nodes and anti odes and SAND in it, cause the sand to clump at the NODES?

Explain in terms of stationary wave
And pressure gradient ?

Answer 2

1) nodes are the point where there is zero amplitude, so area of least energy
2) therefore the sand moves to area of least energy as that’s how physics works in life

In terms of pressure?
- nodes are areas of lowest pressure gradient thus they collect there?

Question 3

MASS PER UNIT LENGTH, if the length can change due to tension and strain, what varibale should we give e it?

If strain decreases what variable in strain equation decreases?

Answer 3

The EXTENSION, not the original lenght

2) the extension again, as that’s the only way (original length can’t change obv)

Question 4

How to describe the potential speeds an electron can be emitted at?

Answer 4

From 0 to max value

Question 5

Principle of superposition!

Answer 5

Is not vector additon of the AMPLITUDES, bevause it’s all displacements !

Remember displacment how far the wave is displaced from EQUILIBRIUM ,
Distance is how far the wave has moved so X DIRECTION

Thus superposition is thr sum of DISPLACEMENT (not restricted to amplitude only)!