Use standing-wave diagrams to track phase and amplitude, calculate allowed frequencies in strings and pipes, and compare resonance and damping responses.
A loudspeaker emits sound of frequency 210 Hz into a pipe with one open and one closed end. The diagram shows a representation of the standing wave established in the pipe.
Outline how the standing wave is formed in the pipe.
Determine the wavelength of the wave.
The solid line represents the standing wave at time t and the dotted line represents the standing wave at an instant later. The dot is the equilibrium position of a particle P in the pipe. The up arrow indicates displacements to the right and the down arrow displacements to the left.
On the diagram, draw
a dot to indicate the approximate position of P at time t,
an arrow to indicate the velocity of P at time t.
The frequency of sound is reduced to 140 Hz . Explain why a standing wave will not be formed in the pipe.
This question is in two parts. Part 1 is about solar radiation and the greenhouse effect. Part 2 is about a mass on a spring.
Part 1 Solar radiation and the greenhouse effect
The following data are available.
The sketch graph below shows how the displacement of the object from point O varies with time over three time periods.
Sketch on the same axes a graph of how the displacement varies with time if a small frictional force acts on the object.
Point P now begins to move from side to side with a small amplitude and at a variable driving frequency f. The frictional force is still small.
At each value of f, the object eventually reaches a constant amplitude A.
The graph shows the variation with f of A.
With reference to resonance and resonant frequency, comment on the shape of the graph.
On the same axes, draw a graph to show the variation with f of A when the frictional force acting on the object is increased.
This question is in two parts. Part 1 is about ideal gases and specific heat capacity. Part 2 is about simple harmonic motion and waves.
Part 1 Ideal gases and specific heat capacity
Simple harmonic motion and waves
W in (a) is immersed in a beaker of oil. As a result of this immersion the oscillations of W are critically damped. Describe what is meant by critically damped.
A loudspeaker emits sound of frequency 210 Hz into a pipe with one open and one closed end. The diagram shows a representation of the standing wave established in the pipe.
Outline how the standing wave is formed in the pipe.
This question is in two parts. Part 1 is about solar radiation and the greenhouse effect. Part 2 is about a mass on a spring.
Part 1 Solar radiation and the greenhouse effect
The following data are available.
Point P now begins to move from side to side with a small amplitude and at a variable driving frequency f. The frictional force is still small.
At each value of f, the object eventually reaches a constant amplitude A.
The graph shows the variation with f of A.
With reference to resonance and resonant frequency, comment on the shape of the graph.