I need this whole lab

Measuring the speed of light with a ehoeolate bar using the Microwave standing wave. Measuring the speed of sound in air using a phone, ear pod, and three toilet paper rolls. Video ipswwwgoutube.comfwatch'?v=ihKYVqij_ig Web site mps:ffwww.npl.eo.ukimeasurement-ar- homeirneasurin -sound-usin -toilet-rolls 1 Place toilet roll on a flat surface with one headphone at the bottom of the tube 2. Stack two more rolls on top to make a tunnel for the sound and help Isolate experimental sound from other noise Stick some Blue Tack on the cable near the other headphone to make it heavier and keep the cable taut 4. Search YouTube for '3 kHz test tone" or nd similar elsewhere 5 Whilst playing the sound, carefully lower the second l'ieadphone into the tube as far as it will go. Slowly raise the headphone. Listen carefully. At one point the sound should almost disappear. Make tiny adjustments to nd the quietest point . Mark the cable at the top of the tube with the pen {or Blue Tack) Move the cable up higher to find the next quietest point, and mark that too . Remove the headphone and measure the distance between the marks in millimetres. This distance is the sounds wavelength Multiply your frequency by the distance {in mm} divided by 10m {to convert mm to metres]. This is your answer speed of sound in metres per second 1i}. You can check by repeating. You could also try other frequencies which will give different wavelengths, but the calcuialion should give the same speed {Try 2 kHz and 4 kHz}