A form of periodic motion in which a point or body oscillates along a line about a central point in such a way that it ranges an equal distance on either side of the central point and that its acceleration towards the central point is always proportional to its distance from it. One way of visualizing SHM is to imagine a point rotating around a circle of radius r at a constant angular velocity ω. If the distance from the centre of the circle to the projection of this point on a vertical diameter is y at time t, this projection of the point will move about the centre of the circle with simple harmonic motion. A graph of y against t will be a sine wave, whose equation is
y = rsinωt
(see diagram). See also pendulum.
Simple harmonic motion
- elements of an orbit
- elevation of boiling point
- Elinvar
- ellipse
- ellipsoid
- elliptical galaxy
- elliptical polarization
- eluate
- eluent
- elution
- elutriation
- eléctrolytic corrosion
- emanation
- emission spectrum
- emissivity
- emittance
- emitter
- emitter follower
- emitter-coupled logic
- empirical
- empirical formula
- emulsion
- enantiomers
- enantiomorphism
- endoergic