C.1.3 - Examples of SHM
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Mass-Spring System
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Today, let's discuss the mass-spring system, which is a quintessential example of simple harmonic motion. Can anyone explain what happens when a mass is attached to a spring and pulled?
The mass will oscillate back and forth.
Exactly! The mass oscillates around an equilibrium position. We can express the period of this motion with the formula T = 2Ο β(m/k). Can someone tell me what the variables stand for?
T is the period, m is the mass, and k is the spring constant.
Correct! Remember, the period increases with more mass and decreases when the spring constant is higher. Now, letβs look at an example: If we have a mass of 2 kg and a spring constant of 50 N/m, what would the period be?
We can calculate it using the formula!
Great! Remember to substitute the values into the formula and calculate it correctly. Now, letβs summarize: We understand how mass and spring constant affect the oscillation period.
Simple Pendulum
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Now, let's shift our focus to another fascinating example β the simple pendulum. Who can describe what happens when a pendulum is displaced from its rest position?
It swings back and forth.
Exactly! The period of a simple pendulum can be expressed as T = 2Ο β(l/g). What do l and g represent?
l is the length of the pendulum and g is the acceleration due to gravity!
Right! An interesting fact is that the period does not depend on the mass of the pendulum bob, just the length. If we have a pendulum of length 1 meter, whatβs the period?
We would plug in the values into the period formula. It should also show us how long it takes to complete a full cycle!
Perfect summary! Remember to consider the small angle approximation for simpler calculations.
Introduction & Overview
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Quick Overview
Standard
In this section, we explore the concepts of simple harmonic motion (SHM) with practical examples, particularly the mass-spring system and simple pendulum. We examine how to calculate their respective periods and the conditions under which they oscillate harmonically.
Detailed
Detailed Summary of Examples of SHM
In this section, we delve into the Examples of Simple Harmonic Motion (SHM). SHM is characterized by the oscillatory nature of systems where the restoring force is directly proportional and opposite to the displacement from an equilibrium position.
1. Mass-Spring System
- A classic example of SHM is the mass-spring system. When a mass is attached to a spring and displaced, it experiences oscillatory motion. The period of oscillation, which is the time taken for one complete cycle, is calculated using the formula:
T = 2Ο β(m/k)
Where:
- T = period (s)
- m = mass attached to the spring (kg)
- k = spring constant (N/m)
This relationship highlights the dependency of the period on both mass and spring stiffness. The greater the mass, the longer the oscillation period, while a stiffer spring (higher k) results in a shorter period.
2. Simple Pendulum
- Another example of SHM is a simple pendulum. When displaced from its resting position, the pendulum swings back and forth exhibiting SHM, particularly for small angular displacements. The formula for calculating the period of a simple pendulum is:
T = 2Ο β(l/g)
Where:
- l = length of the pendulum (m)
- g = acceleration due to gravity (approximately 9.81 m/sΒ²)
The period of a simple pendulum is independent of the mass of the pendulum bob, relying solely on the length of the pendulum and the constant acceleration due to gravity.
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Mass-Spring System
Chapter 1 of 2
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Chapter Content
β Mass-Spring System: A mass attached to a spring oscillates with a period:
T=2ΟmkT = 2Οβ(m/k)
Detailed Explanation
A mass-spring system is a classic example of simple harmonic motion (SHM). When a mass is attached to a spring and pulled or compressed, it will oscillate back and forth around its resting position due to the restoring force of the spring. The equation shown, T = 2Οβ(m/k), gives the period T of the motionβhow long it takes for the mass to complete one full cycle of oscillation. Here, m is the mass being oscillated, and k is the spring constant, which measures how stiff the spring is.
Examples & Analogies
Imagine a child on a swing. When pushed, the swing moves back and forth around its resting position, similar to how a mass on a spring oscillates. The time it takes to go from one side to the other (the period) depends on how heavy the child is (mass) and how strong the swing's support is (spring constant).
Simple Pendulum
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Chapter Content
β Simple Pendulum: For small angles, a pendulum exhibits SHM with a period:
T=2ΟlgT = 2Οβ(l/g)
Detailed Explanation
A simple pendulum consists of a weight (or bob) suspended from a pivot point, allowing it to swing back and forth under the influence of gravity. For small angles of swing, the motion of the pendulum can be approximated as SHM. The formula T = 2Οβ(l/g) describes the period of the pendulum's oscillation, where l is the length of the pendulum, and g is the acceleration due to gravity (approximately 9.81 m/sΒ²). It shows that the period depends on the length of the pendulum; longer pendulums swing more slowly, while shorter ones swing faster.
Examples & Analogies
Think of a grandfather clock. The pendulum inside swings back and forth to keep time. If the pendulum is longer, it takes more time to complete one swing compared to a shorter pendulum, much like how a swing set will swing differently based on the length of the chain it hangs from.
Key Concepts
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Mass-Spring System: A mass attached to a spring oscillates and has its period defined by T = 2Ο β(m/k).
-
Simple Pendulum: A pendulum that swings back and forth in SHM with a period given by T = 2Ο β(l/g).
Examples & Applications
Example 1: A mass of 2 kg attached to a spring with a spring constant of 50 N/m has a period of T = 2Ο β(2 kg / 50 N/m).
Example 2: A simple pendulum of length 1 m exhibits SHM with a period of T = 2Ο β(1 m / 9.81 m/sΒ²).
Memory Aids
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Rhymes
In spring, the mass does swing, / Periods found, it's a simple thing.
Stories
Imagine a mass on a spring, / Bouncing high, it wants to cling, / With each step down and back again, / The periodβs set by mass and spring.
Memory Tools
For SHM remember: 'Timeβs Pretty (T = 2Ο β(m/k or l/g))', focusing on T and what affects it.
Acronyms
SIMPLE
'S' for Spring
'I' for Inertia (mass)
'M' for Motion
'P' for Period
'L' for Length (in Pendulum)
'E' for Energy involved in the system.
Flash Cards
Glossary
- Simple Harmonic Motion (SHM)
A type of periodic motion where the restoring force acting on an object is directly proportional to its displacement from the equilibrium position.
- MassSpring System
A system consisting of a mass attached to a spring, undergoing oscillatory motion.
- Period (T)
The time required for one complete cycle of motion.
- Spring Constant (k)
A measure of a spring's stiffness, defined as the force required to stretch or compress the spring by a unit distance.
- Simple Pendulum
A weight suspended from a pivot point that swings back and forth under the influence of gravity.
- Acceleration due to Gravity (g)
The acceleration experienced by a free-falling object, approximately 9.81 m/sΒ² near the Earth's surface.
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