How can we explain the standing waves on a string?

When a wave reaches the end of a string, it is reflected and inverted, so in a fixed string in which we've caused vibrations, such as a guitar string, we have two sinusoidal waves travelling in opposite directions. In certain places, where the two waves are exactly out of phase, we observe destructive interference (crest meets trough, and the two waves cancel each other out) and the point remains static. These points are called nodes. Midway between them, we can observe the opposite: constructive interference (where the two waves coincide and produce an even bigger displacement); these points of greatest amplitude are called antinodes. The fixed ends of the string are always nodes, and the number of nodes and antinodes depends on how long the string is relative to the wavelength. For example, in a string which is one-half wavelength long, we have two nodes (at both ends of the string) and one antinode; if the string is one wavelength long, we have three nodes and two antinodes, and so on.

Answered by Boris A. Physics tutor

2192 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

A car is moving along a straight horizontal road, with a constant acceleration. The car passes point A, with a speed of ums(-1). 10 seconds later, passes point B, with a speed of 45 ms(-1). The distance from A to B is 300m. Find u.


Two trains are heading in opposite directions on the same track. Train X has a mass of 16000kg and a speed of 2.8m/s. Train Y has a mass of 12000kg and a speed of 3.1m/s. At what speed do the joined trains move off together immediately after the collison?


A ball is launched from ground level at 5m/s at an angle of 30 degrees above the horizontal. What is its height above ground level at the highest point in its trajectory?


If a bulb has a current of 20mA and voltage of 5V, and the current cost of electricity is £3 for a kW/hour. How much money would you spend to power the bulb for 8 hours? Are these good estimates for the current, voltage and cost of electricity?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences