Measuring waves on a string | Starter Quiz | Oak National Academy

Waves on a string are {{}} waves.

• transverse

• longitudinal

• electromagnetic

Answer explanation

Waves on a string are transverse because the oscillation will be 90 degrees to the direction the wave travels (along the string).

What is 12 cm in metres?

• 0.012 m

• 0.12 m

• 1.20 m

• 12 m

• 12 000 m

Answer explanation

There are 100 cm in 1 metre, so a measurement in cm needs to be divided by 100 to get the same measurement in metres. In this case, 12/100 = 0.12 cm. Alternatively: 1 cm = 0.01 m, so 12 cm = 0.12 m.

Some waves on a string have a frequency of 3 Hz and a wavelength of 12 cm. How would you calculate the wave speed in m/s?

• 3 x 12

• 3 x 0.12

• 3 ÷ 12

• 3 ÷ 0.12

• 0.12 ÷ 3

Answer explanation

wave speed = frequency x wavelength, and wavelength must be in m to give wave speed in m/s. 12 cm = 0.12 m, so frequency x wavelength = 3 x 0.12 (= 0.36 m/s)

In experiments, what are the different types of variables?

• dependent variable

• what you change in each test to see what effect it has

• control variables

• what you keep the same so they don't affect the results

• independent variable

• what you monitor to see if it changes in response

Answer explanation

Control variables are what you have to keep the same in each test so they don't affect the result. Independent variables are what you choose to change and dependent variables are what you monitor to see how they respond.

When a wave travels along a string, what is the wave medium?

• the middle point of a wave, halfway along a wavelength

• the frequency of the wave

• the string

• the equilibrium position

Answer explanation

The material a wave is travelling through is called the wave medium, so for a wave on a string, the medium is the string.

If waves of different frequencies and wavelengths all have the same speed, what happens if you increase the frequency of waves?

• increasing the frequency also increases the wavelength

• increasing the frequency decreases the wavelength

• increasing the frequency does not affect the wavelength

Answer explanation

If waves of different frequencies and wavelengths all have the same speed, frequency and wavelength are inversely proportional, so increasing one decreases the other to give the same wave speed according to: wave speed = frequency x wavelength.