Karteikarten
Simple Harmonic Motion
Karten in diesem Stapel (37)
- 1What is simple harmonic motion?The oscillation of an object where the object's acceleration is directly proportional to its displacement from its equilibrium position, and is always directed towards the equilibrium.
- 2What is the equilibrium position in SHM?The midpoint of the object's motion.
- 3What is the displacement in SHM?The distance of the object form the equilibrium position.
- 4What causes the to object accelerate towards the equilibrium in SHM?A restoring force pulling or pushing the object back towards the equilibrium position.
- 5What does the size of the restoring force in SHM depend on?The displacement.
- 6Why is the acceleration in SHM directly proportional to the negative displacement?Because the displacement is always opposing the displacement.
- 7How does displacement vary with time as a graph? What is the maximum value?It varies as a cosine or sine graph. The maximum value is A, the amplitude.
- 8What is the gradient of the displacement against time graph for SHM? What is the maximum value?The velocity.
ωA, where ω is the angular frequency of the oscillation. - 9What is the gradient of the velocity against time graph for SHM? What is the maximum value?The acceleration.
ω^2A. - 10What does the velocity against time graph for SHM look like if the displacement-time graph looks like the graph below?
- 11What does the acceleration against time graph for SHM look like if the displacement-time and velocity-time graphs looks like the graphs shown?
- 12What is phase difference? What can it be measured in?A measure of how much one wave lags behind another wave. Radians, degrees, or fractions of a cycle.
- 13If two waves are exactly out of phase (in antiphase) what is the phase difference?π radians or 180°.
- 14What is the phase difference between the velocity-time and displacement-time graphs?π/2 radians.
- 15What is the phase difference between the acceleration-time and displacement-time graphs?π radians - it is in antiphase.
- 16What is a cycle of oscillation for SHM?From maximum positive displacement (e.g. maximum displacement to the right) to maximum negative displacement (e.g. maximum displacement to the left) and back again.
- 17What is the frequency of SHM?The number of cycles per second.
- 18What is the period of SHM?The time taken for a complete cycle in seconds.
- 19What is the amplitude of an oscillation in SHM?The maximum magnitude of displacement.
- 20In SHM how are the frequency and period related to the amplitude?They are independent from each other. So frequency and period and constant for a given oscillation.
- 21What does the type of potential energy depend on in SHM? What is it for pendulums and for masses on springs?What's providing the restoring force.
For pendulums it's gravitational potential energy and for masses on springs it's elastic strain energy and possibly gravitational potential energy. - 22What happens to the energy: 1. as an object moves towards the equilibrium position? 2. at equilibrium 3. as an object is moving away from equilibrium? 4. at maximum displacement (the amplitude)?1. The restoring force does work on the object and so transfers some Ep to Ek.
2. The object's Ep is said to be zero and Ek is maximum - therefore its velocity is maximum.
3. The Ek is converted back to Ep.
4. The objects Ep is maximum, and its Ek is zero - so its velocity is zero. - 23What does a graph showing how the kinetic and potential energy of an object in SHM change with displacement look like?
- 24What is the sum of the potential and kinetic energy called?The mechanical energy.
- 25What does a graph showing how the kinetic and potential energy of an object in SHM change with time look like?
- 26To understand the Maths behind SHM it can be useful to think about it as...the 'projection' of circular motion onto horizontal plane.
- 27If you imagine a ball spinning in a circle along the same plane. From the side (i.e. the plane of rotation) what will it look like? When will it appear fastest and when will appear slowest?Its oscillating from side to side, and moving with SHM.
It will it appear fastest when x = 0 and slowest when x = +/- A. - 28Using circular motion how do you get to the equation x = Acos(ωt)?Displacement is equal to horizontal components the balls position so x = rcosθ
The radius, r is the same as the amplitude of the ball's simple harmonic motion A.
ω = θ/t so θ = ωt.
x = rcosθ
using the above x = Acos(ωt)
- 29Only when can you use the equation x = Acos(ωt)?Only if you start timing when the pendulum is at its maximum displacement - i.e. when t = 0 and x = +/-A.
- 30What is ω in SHM? How is it different to ω in circular motion?ω is angular frequency. It has the same value, units and symbol as angular velocity, just a different name.
- 31What is the condition equation and the defining equation for SHM?Conditioning : a ∝ -x
Defining : a = −ω(^2)x - 32What is a mass on a spring?A simple harmonic oscillator (SHO).
- 33For a mass on a spring how do you calculate the size of the restoring force?Using Hooke's law:
F = kΔL - 34Is a pendulum a SHO (simple harmonic oscillator)?Yes.
- 35What is another setup you can use to investing SHM?A U-tube containing some water.
- 36Explain how a U-tube containing some water undergoes SHO?When at equilibrium, the levels of the water on either side of the tube are equal. When the water is pushed down on one side of the tube, the water level on the opposite side rises. When the pressure is then released, the water undergoes SHO.
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- Beschreibung
- A2 Physics (A2 Further Mechanics) Karteikarten am Simple Harmonic Motion, erstellt von Jasmine Bayliss-Dagg am 20/10/2017.
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- Jasmine Bayliss-Dagg
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