Waves & Oscillations Flashcards
What is simple harmonic motion and its conditions?
It is periodic motion around a central point of equilibrium where there is no net force.
The object must follow a cyclical path.
There is a restoring force directed towards the point of equilibrium, which is directly proportional to the displacement from the point of equilibrium which acts in the opposite direction.
(a is proportional to -x)
What is the amplitude of simple harmonic motion?
The maximum displacement from the point of equilibrium.
What is the period of the wave?
The amount of time taken to complete one full cycle.
What is the frequency of a wave?
The amount of repetitions a cycle completes in one second.
Hz = events per second.
What is the period in simple harmonic motion?
The time taken for the oscillation to travel to both extremes and then back to its starting point.
What does the position-time graph of an object in simple harmonic motion look like?
A sine graph where the amplitude is the total displacement from the point of equilibrium and the period is the time taken to complete 1 cycle
The nodes of the wave is where the object is at its starting point.
What information can be concluded from the displacement, velocity and acceleration time graphs?
The velocity is constant and highest at the equilibrium point and zero at the extrema.
The acceleration is the highest at the extrema where the object is not moving and zero at the equilibrium point where the object is moving the fastest.
Why is the acceleration the greatest at the extrema?
As F = ma, as the mass is constant and the force is at its maximum at the extrema thus showing how acceleration must also be at its maximum.
There is no net force at the equilibrium
Why does the object slow down after passing through the point of equilibrium?
As the force is proportional to the displacement in the opposite direction, as the displacement from the equilibrium point increases- the force acting towards the equilibrium point also increases, therefore causing the object to slow down as acceleration acts oppositely to the direction of its motion.
How would the force time graph of an object in simple harmonic motion look like?
Like the acceleration-time graph.
As energy is scalar, the graph cannot have negative x and y values.
The maximum of potential energy graph is equivalent to the minima of the kinetic energy graph.
If the two graphs are superimposed, they have an equal height which signifies the conservation of energy.
What is the definition of a wave?
A disturbance that carries energy through a medium without carrying matter along with it. All particles in the wave exist in simple harmonic motion.
What is the difference between a transverse and longitudinal wave?
A transverse wave oscillates in the direction perpendicular to its motion.
A longitudinal wave oscillates in the direction parallel to its motion.
What is the difference between mechanical and electromagnetic waves?
A wave that requires a medium to move through is mechanical but can be transverse/longitudinal.
A EM wave requires no medium to travel through and can move through empty space at the speed of light.
How can the velocity of a wave be derived?
In one full period of reptation, a wave moves exactly one wavelength of displacement.
V= d/t and t = 1/f
Therefore, the velocity is equal to the product of the wavelength and frequency
What can be concluded from the displacement- distance graph of a wave?
The amplitude and wavelength as it is a 2D picture of the real wave.
