Springs and Hooke’s Law Physics 11. Newton’s Cradle  Explain this…  0HZ9N9yvcU.

Slides:



Advertisements
Similar presentations
Work, Energy, And Power m Honors Physics Lecture Notes.
Advertisements

Chapter 5 – WORK and ENERGY. 5.2 MECHANICAL ENERGY.
Energy Chapter 5. What is energy? The property of an object that allows it to produce a change in itself or its environment. The property of an object.
Energy Chapter 5. Mechanical Energy Energy due to movement or position. Energy due to movement or position. Kinetic Energy – energy of motion Kinetic.
More Conservation of Mechanical Energy
ENGR 215 ~ Dynamics Sections 14.1 – Conservation of Energy Energy can neither be created nor destroyed during a process, it can only change forms.
Principles of Physics - Foederer. Energy is stored in a spring when work is done to compress or elongate it Compression or elongation= change in length.
Example: A 20 kg block is fired horizontally across a frictionless surface. The block strikes a platform that is attached to a spring at its equilibrium.
Simple Harmonic Motion & Elasticity
Oscillations Phys101 Lectures 28, 29 Key points:
PHYSICS InClass by SSL Technologies with S. Lancione Exercise-42
Work and Energy. Outcomes Upon completion of this unit you will be able to: Analyze force problems in terms of energy. Define the term "work" as it relates.
Physics 6A Work and Energy examples Prepared by Vince Zaccone For Campus Learning Assistance Services at UCSB.
Springs and Hooke’s Law
Work. Work is the product of the magnitude of the __________________ moved times the component of a ________________ in the direction of the ________________.
Bellringer 10/25 A 95 kg clock initially at rest on a horizontal floor requires a 650 N horizontal force to set it in motion. After the clock is in motion,
WORK AND ENERGY 1. Work Work as you know it means to do something that takes physical or mental effort But in physics is has a very different meaning.
ADV PHYSICS Chapter 5 Sections 2 and 4. Review  Work – force applied over a given distance W = F Δ x [W] = Joules, J  Assumes the force is constant.
Elastic Force and Energy Stretching or Compressing a spring causes the spring to store more potential energy. The force used to push or pull the spring.
Preview Objectives Definition of Work Chapter 5 Section 1 Work.
Energy m m Physics 2053 Lecture Notes Energy.
Physics 3.3. Work WWWWork is defined as Force in the direction of motion x the distance moved. WWWWork is also defined as the change in total.
AP Physics C I.C Work, Energy and Power. Amazingly, energy was not incorporated into physics until more than 100 years after Newton.
Hooke’s Law and Elastic Potential Energy
Mechanical Energy Pt. 2 Week.
Review and then some…. Work & Energy Conservative, Non-conservative, and non-constant Forces.
Simple Harmonic Motion
Simple Harmonic Motion Chapter 12 Section 1. Periodic Motion A repeated motion is what describes Periodic Motion Examples:  Swinging on a playground.
Periodic Motion. Definition of Terms Periodic Motion: Motion that repeats itself in a regular pattern. Periodic Motion: Motion that repeats itself in.
Energy 4 – Elastic Energy Mr. Jean Physics 11. The plan:  Video clip of the day  Potential Energy  Kinetic Energy  Restoring forces  Hooke’s Law.
Work has a specific definition in physics. Work is done anytime a force is applied through a distance.
Copyright © 2009 Pearson Education, Inc. Oscillations of a Spring Simple Harmonic Motion Energy in the Simple Harmonic Oscillator The Simple Pendulum Lecture.
Introduction to Simple Harmonic Motion Unit 12, Presentation 1.
Simple Harmonic Motion
Work has a specific definition in physics
Lecture 12: Elastic Potential Energy & Energy Conservation.
© Houghton Mifflin Harcourt Publishing Company Preview Objectives Definition of Work Chapter 5 Section 1 Work.
Elastic Potential Energy Pg Spring Forces  One important type of potential energy is associated with springs and other elastic objects. In.
3/18 do now – on a new sheet 1.A negatively charged rod is brought near a neutral object without touching it. The overall charge on the object will become.
Examples: Mechanical Energy Conservation
Phys 250 Ch14 p1 Chapter 13: Periodic Motion What we already know: Elastic Potential Energy energy stored in a stretched/compressed spring Force: Hooke’s.
Chapter 5.2 Hooke’s Law WOD are underlined. Question What is the net force on this mass?
Work and Energy. Section Objectives: Define work by relating it to force and displacement. Identify where work is being performed in a variety of situations.
Physics Section 5.2 Define and apply forms of mechanical energy. Energy is the ability to do work. Kinetic energy is the energy of an object due its motion.
Springs and Hooke’s Law Physics 11. Springs A mass-spring system is given below. As mass is added to the end of the spring, what happens to the spring?
Chapter 16 Vibrations Motion. Vibrations/Oscillations Object at the end of a spring Object at the end of a spring Tuning fork Tuning fork Pendulum Pendulum.
Elastic Potential Energy. Elastic potential energy is the energy stored in elastic materials as the result of their stretching or compressing. Elastic.
Work and Potential Energy. Outline what is meant by change in gravitational potential energy. State and apply how Work is equivalent to Potential Energy.
Elastic Energy SPH3U. Hooke’s Law A mass at the end of a spring will displace the spring to a certain displacement (x). The restoring force acts in springs.
Physics Section 11.1 Apply harmonic motion
Simple Harmonic Motion
Springs And pendula, and energy.
Chapter 5 Section 1 Work Preview Objectives Definition of Work.
PHYSICS InClass by SSL Technologies with Mr. Goddard Hooke's Law
Springs Forces and Potential Energy
Elastic Forces Hooke’s Law.
Chapter 11: Vibrations and Waves Section 1: Simple Harmonic Motion
Simple Harmonic Motion (SHM)
Hooke's Law When a springs is stretched (or compressed), a force is applied through a distance. Thus, work is done. W=Fd. Thus elastic potential energy.
Bell Ringer: What is a force? What is Newton’s 2nd Law? What is work?
Chapter 5 Pgs
ELASTIC FORCE The force Fs applied to a spring to stretch it or to compress it an amount x is directly proportional to x. Fs = - k x Units: Newtons.
Energy Spring Force & Elastic Potential Energy.
Elastic Potential Energy
Springs and Hooke’s Law
Conservation Laws Elastic Energy
Unit 5 ENERGY.
F = k x Springs  Web Link: Introduction to Springs
Ch. 12 Waves pgs
Presentation transcript:

Springs and Hooke’s Law Physics 11

Newton’s Cradle  Explain this…  0HZ9N9yvcU

Springs A mass-spring system is given below. As mass is added to the end of the spring, what happens to the spring? WHY???

Springs

 2 times the mass results in a 2 times of the displacement from the equilibrium point…  3 time the mass… 3 times the displacement…

What kind of energy is this?  Potential Energy Elastic Potential Energy to be exact!

What else besides springs has elastic potential energy?  Diving boards  Bows (bow and arrows)  Bungee cord

Hooke’s Law F spring : Applied force X : displacement of the spring from the equilibrium position (units: m) K: the spring constant (units: N/m) The spring constant is unique to the spring (similar to coefficient of friction).

Example  An archery bow requires a force of 133N to hold an arrow at “full draw” (pulled back 71cm). Assuming that the bow obeys Hooke’s Law, what is its spring constant?

 F = kx  133 = k(0.71)  k = 133/0.71  k = N/m  190 N/m

Practice Problems  Textbook Page 258  35-37

 XnbvZx9iWs

Restoring Force  The restoring force is the force that is needed to put the spring back to equilibrium. Usually it opposes gravity so it is a positive force.  Example: If you stretch a spring by 0.5m and you had to use 150N of force, the restoring force is -150N.

Hooke’s Law  The restoring force is opposite to the applied force. (negative sign) Gravity applied in the negative direction, the restoring force is in the positive direction

Elastic Potential Energy of a Spring  Formula: E e = ½ kx 2  Units: Joules (J)

Example:  A spring with spring constant 75 N/m is resting on a table.  A) If the spring is compressed a distance of 28cm, what is the increase in its potential energy?  B) What force must be applied to hold the spring in this position?

Answer:  A) E e = ½ kx 2  E e = ½ (75)(0.28) 2  E e = 2.9 J  B) F = kx  F= 75(0.28)  F = 21 N

Practice Problems  Page 261, questions 38, 39, 40  Page 261 (Section Review) 1, 2, 3, 4, 7

Conservation of Energy with a Spring  Ex. 1: A 4.0 kg block slides across a frictionless table with a velocity of 5.0m/s into a spring with a stiffness of 2500 N/m. How far does the spring compress?

Answer  X = 0.20m

Example 2:  A 70. kg person bungee steps off a 50.m bridge with his ankles attached to a 15m long bungee cord. Assume the person stops at the edge of the water and he is 2.0m tall, what is the force constant of the bungee cord?

 Answer: 64 N/m  Conservation of Energy Worksheet

Practice Problems  Textbook Page 261  Section review (p 261)  1-10