Wave Lab

Wave Lab is a GCSE physics game about waves, wave speed and the electromagnetic spectrum. Grid-reading questions show a still wave on a grid. Calculation questions show their own values with units.

Answer ten questions, each with four options. Some ask you to use the wave speed equation, v = f λ, to find a speed, a frequency or a wavelength. Others ask for the period of a wave, or for the wavelength or amplitude of the wave on the grid. The rest cover the electromagnetic spectrum: the order of its parts, and what each part is used for.

The values come with prefixes such as kHz, MHz, cm and nm, and speeds are often in km/s. Convert them before you calculate. In the wave speed questions, the first three of the round give lengths in metres, the middle four use centimetres and the last three use nanometres. The Challenge start skips the metres. The questions that ask you to read the grid draw the wave you need to measure.

You have 15 seconds for each question. A right answer in time scores 15 points. When the time runs out, the question counts as wrong. With the practice switch on there is no timer, and a right answer scores 10. After a wrong answer, the game shows the right one before you move on.

A wave carries energy from one place to another. Its frequency is the number of waves that pass a point each second, in hertz (Hz). Its wavelength is the distance from a point on one wave to the same point on the next, such as crest to crest. The amplitude is the largest distance a point moves away from its rest position. The wave in the game is transverse: each point moves up and down while the wave travels along the grid.

Wave speed links frequency and wavelength: wave speed = frequency × wavelength, or v = f λ. A wave of 5 Hz with a wavelength of 2 m travels at 10 m/s. To find the frequency, divide the speed by the wavelength. To find the wavelength, divide the speed by the frequency. The wave speed equation page shows the equation in the form each board prints it.

The period is the time for one whole wave to pass. It is 1 divided by the frequency, T = 1 ÷ f, so a 4 kHz wave has a period of 1 ÷ 4,000 = 0.00025 s. AQA 8463 lists this equation in 4.6.1.2.

Prefixes are behind a lot of wrong answers. 1 kHz is 1,000 Hz and 1 MHz is 1,000,000 Hz. 1 cm is 0.01 m and 1 nm is 0.000000001 m. A speed of 1 km/s is 1,000 m/s. The game offers the answer you would get without converting, so check every unit first.

Light is one part of a continuous electromagnetic spectrum. From the longest wavelength to the shortest, which is also from the lowest frequency to the highest, the order is radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays. AQA gives this order in 4.6.2.1, Edexcel 1PH0 in 5.10 and 5.11, and OCR J249 in P5.2.

Each part of the spectrum has uses. The uses in the game come from the specifications. For example, Edexcel 1PH0 point 5.22 lists airport security scanners for X-rays and sterilising medical equipment for gamma rays, and AQA 8463 lists uses in 4.6.2.4.

• Write v = f λ before you start. To find v, multiply. To find f or λ, divide.
• Change every value into Hz, m and m/s before you put it in the equation.
• To read a wavelength off the grid, measure from one crest to the next crest. Measuring half a wave is a common slip.
• Amplitude goes from the middle line up to a crest. If you measure from a crest down to a trough, you get twice the amplitude.
• For the spectrum, fix one end in your head. Radio waves have the longest wavelength and the lowest frequency, and gamma rays have the shortest wavelength and the highest frequency.

On the grid, measure between neighbouring crests to find the wavelength.