Core Practical: Investigating Wave Properties Flashcards

All 5 cards in this deck

What equipment is used to produce and observe waves in a fluid in the core practical?

A ripple tank with a motorised dipper or bar (driven by a signal generator) and a lamp above to project the ripples onto a screen.

What are the steps to find the speed of ripples in a ripple tank using $v = f\lambda$?

e.g. ripples with 50 waves passing a point in 10 s

1. Frequency $=$ waves counted $\div$ time $= 50 \div 10 = 5$ Hz.
2. Measure 5 wavelengths on the screen and divide by 5: $\lambda = 0.04$ m.
3. $v = f\lambda = 5 \times 0.04 = 0.2$ m/s

What equipment is used to make and measure waves in a solid in the core practical?

A signal generator and vibration generator attached to a stretched string (with masses over a pulley); the frequency is read from the signal generator.

What is the main difficulty in measuring the wavelength of ripples in a ripple tank, and one improvement?

The ripples move too fast to measure clearly; use a strobe light (or film them and freeze the frame) to make the pattern appear still.

True or false? Measuring the length of ten wavelengths and dividing by ten reduces the percentage error in the wavelength.

True. The measured length is larger, so the uncertainty in the ruler reading is a smaller proportion of it.