Practice Flashcards
Flip to reveal answersWhat two forms of energy interchange during SHM?
Track your progress — Sign up free to save your progress and get smart review reminders based on spaced repetition.
All 15 Flashcards — Energy in simple harmonic motion
Sign up free to track progress and get spaced-repetition review schedules.
Question
What two forms of energy interchange during SHM?
Answer
**Kinetic energy** (of motion) and **potential energy** (stored, e.g. in a stretched spring). They swap back and forth as it oscillates.
Question
What happens to the total energy of an oscillation (no friction)?
Answer
It **stays constant** — KE and PE just trade places, but their sum never changes.
Question
Where in the swing is the kinetic energy greatest?
Answer
At the **centre** (equilibrium position), where the object moves **fastest**.
Question
Where in the swing is the potential energy greatest?
Answer
At the **ends** (the amplitude), where the object is **momentarily at rest**.
Question
What is the amplitude of an oscillation?
Answer
The **greatest displacement** from the centre — the turning point where the object briefly stops.
Question
Formula for the total energy of a mass-spring oscillation?
Answer
$E_{total} = \tfrac{1}{2}kA^{2}$ — set by the amplitude A. It is the data booklet's elastic PE ½kΔx² at Δx = A.
Question
Why does E_{total} = ½kA²?
Answer
At the amplitude the object is at rest (KE = 0), so all the energy is the elastic PE stored at the biggest stretch, ½kx² with x = A.
Question
How do you find the maximum speed of an oscillator?
Answer
Set the **maximum KE equal to the total energy**: ½mv_{max}² = ½kA², then solve for v_{max}.
Question
Double the amplitude — what happens to the total energy?
Answer
It becomes **four times larger**, because E_{total} = ½kA² depends on A² (the amplitude squared).
Question
What is the kinetic energy at the centre, in terms of the total energy?
Answer
It **equals the total energy** — at the centre the PE is zero, so all the energy is kinetic.
Question
What shape is the energy-against-displacement graph for KE and PE?
Answer
**PE** is an upward parabola (min at the centre); **KE** is a downward parabola (max at the centre); their sum is a flat line.
Question
Most common SHM-energy mistake?
Answer
Thinking the speed is greatest at the ends — it is greatest at the **centre**; at the ends the object is momentarily still.
Question
How often does the kinetic energy of an oscillator peak?
Answer
**Twice every period**: each time it passes the centre, in either direction.
Question
Starting at the centre, what are KE and PE at t = 0?
Answer
**KE is maximum and PE is zero**: all the energy is kinetic at the centre.
Question
Which energy stores swap in a mass on a vertical spring?
Answer
**Kinetic, elastic potential and gravitational potential** energy; their total stays constant.
Read the notes
Full study notes for Energy in simple harmonic motion
Topic 3.1 hub
Simple harmonic motion
More from Topic 3.1
All flashcards in this topic
Physics exam skills
Paper structures & tips
Track your progress with spaced repetition
Sign up free — Aimnova tells you exactly which cards to review and when, so you remember everything before your IB exam.
Start Free