11. Waves & oscillations Flashcards
What is simple harmonic motion?
An object that moves back and forth with the same amplitude around an equilibrium position.
What is an example of simple harmonic motion?
A spring.
Which force acts to return an object to equilibrium through simple harmonic motion?
Restoring force.
Whose law shows that in simple harmonic motion, the restorative force is directly proportional to both the spring constant and displacement of equilibrium?
Hooke’s law.
In Hooke’s law, what is the spring constant?
The stiffness of a spring.
What is a period?
The time for one complete cycle of vibration.
What is frequency?
The number of complete vibrational cycles per unit of time, usually 1 second.
What is the period of a pendulum?
The time it takes a pendulum to return to its original position.
A pendulum swings from its starting point, through equilibrium, to what height on the other side?
The same height.
What is the period of a spring?
The time it takes a spring to return to its original position.
How do you measure the speed of a wave?
Frequency times wavelength.
What are the 2 types of wave?
Mechanical (such as those in water or sound) and electromagnetic waves (such as light).
What are the 2 main types of mechanical wave?
Longitudinal and transverse.
What is a mechanical wave?
It needs a medium to travel through.
What happens in longitudinal waves?
Medium moves parallel to wave motion.
What are transverse waves?
Medium moves perpendicular to wave motion.
What is wavelength?
Distance between 2 consecutive points at the same position in the wave cycle.
What is amplitude?
The height of the wave measured from the equilibrium to the highest or lowest displacement.
What is a crest?
The highest displacement of the medium.
What is a trough?
The lowest displacement of the medium.
What is wave interference?
When 2 waves overlap to form a resultant wave.
What are the 2 types of wave interference?
Constructive and destructive.
What happens with constructive wave interference?
A larger amplitude.
What happens with destructive wave interference?
A smaller amplitude or, if they have the same amplitude, they cancel each other out.
What forms when 2 waves of the same amplitude and frequency, travelling in opposite directions, overlap?
Standing waves.
What makes standing waves appear to be standing still?
Nodes and antinodes.
What are nodes?
Fixed positions of complete destructive interference.
What are antinodes?
Positions of maximum constructive interference.
What are electromagnetic waves?
Electric and magnetic fields that change constantly and are positioned 90 degrees to each other.
What organises all electromagnetic radiation waves by their wavelength and frequency?
Electromagnetic spectrum.
