An object oscillates with simple harmonic motion - Edexcel - A-Level Physics - Question 9 - 2023 - Paper 2
Question 9
An object oscillates with simple harmonic motion. The object has kinetic energy $E_k$ and displacement $x$.
Which of the following graphs shows the variation of $E_... show full transcript
Worked Solution & Example Answer:An object oscillates with simple harmonic motion - Edexcel - A-Level Physics - Question 9 - 2023 - Paper 2
Step 1
Identify Kinetic Energy in Simple Harmonic Motion
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Answer
In simple harmonic motion (SHM), the kinetic energy of an object varies with its displacement from the equilibrium position. The kinetic energy (Ek) can be expressed as:
E_k = rac{1}{2} k (A^2 - x^2)
where:
k is the spring constant,
A is the amplitude of the motion,
x is the displacement.
From this expression, it can be seen that as displacement x increases towards the amplitude A, the kinetic energy Ek decreases to zero at maximum displacement.
Step 2
Analyze Graphs for Variation of Kinetic Energy
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Answer
Looking at the nature of the kinetic energy expression in SHM, we know that it forms a parabola. As x approaches A, Ek approaches zero. The correct graph will show Ek decreasing quadratically as x approaches the amplitude, indicating that the kinetic energy at maximum displacement is zero.
Among the provided graphs, Graph B represents this parabolic behavior where the kinetic energy decreases as displacement increases.
Step 3
Select the Correct Graph
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Answer
Therefore, the graph that correctly shows the variation of Ek with respect to x is Graph B.