Potential Energy and Energy Conservation

Slides:



Advertisements
Similar presentations
Mr. Jean November 21 st, 2013 IB Physics 11 IB Physics 11.
Advertisements

Physics 111: Mechanics Lecture 7
Conservation of Energy Chapter 11 Conservation of Energy The Law of Conservation of Energy simply states that: 1.The energy of a system is constant.
Please Compute… A man cleaning a floor pulls a vacuum cleaner with a force of magnitude 50 N at an angle of 30 degrees to the horizontal. Calculate the.
Kinetic energy. Energy Energy is usually defined as the capacity to do work. One type of energy is kinetic energy.
Work, Energy, And Power m Honors Physics Lecture Notes.
Energy and Energy Transfer
Mechanical Kinetic, Potential (gravitational, elastic) Thermal Chemical Electromagnetic Nuclear Forms of Energy Energy is conserved!
More Conservation of Mechanical Energy
Chapter 7 Energy of a System.
Work and Kinetic Energy. Work Done by a Constant Force The definition of work, when the force is parallel to the displacement: (7-1) SI unit: newton-meter.
1a. Positive and negative work
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
Chapter 7 Work and Kinetic Energy. Units of Chapter 7 Work Done by a Constant Force Kinetic Energy and the Work-Energy Theorem Work Done by a Variable.
Chapter 7 Energy of a System.
Chapter 6 Work & Energy.
Chapter 6 Energy and Oscillations
Physics 111: Mechanics Lecture 6 Wenda Cao NJIT Physics Department.
Chapter 5 – Work and Energy If an object is moved by a force and the force and displacement are in the same direction, then work equals the product of.
Chapter 6 Energy and Energy Transfer. Introduction to Energy The concept of energy is one of the most important topics in science Every physical process.
Chapter 6 Work and Energy.
Ch 6 Work and Energy.
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.
Potential Energy and Conservative Forces
Chapter 5 Work and Energy. 6-1 Work Done by a Constant Force The work done by a constant force is defined as the distance moved multiplied by the component.
Mechanics Work and Energy Chapter 6 Work  What is “work”?  Work is done when a force moves an object some distance  The force (or a component of the.
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.
Work and Power Chapter 5. Work Work is done when a force causes a displacement in the direction of the force W = Fd (force and displacement parallel)
Chapter 7 Energy of a System. Introduction to Energy A variety of problems can be solved with Newton’s Laws and associated principles. Some problems that.
Chapter 7 Energy of a System. The concept of energy is one of the most important topics in science and engineering Every physical process that occurs.
Hooke’s Law and Elastic Potential Energy
Work and Energy An Introduction.
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.
Mechanics 105 Work done by a constant force Scalar product Work done by a varying force Kinetic energy, Work-kinetic energy theorem Nonisolated systems.
Simple Harmonic Motion
Work-2 & Power. Work and Area If the force is constant, we can graphically interpret the work done ( W = F d ) as the area of a rectangle F tall and d.
Copyright © 2012 Pearson Education Inc. PowerPoint ® Lectures for University Physics, Thirteenth Edition – Hugh D. Young and Roger A. Freedman Lectures.
Conservative Forces: The forces is conservative if the work done by it on a particle that moves between two points depends only on these points and not.
1 Chapter 6 Energy and Energy Transfer 2 3 Introduction to Energy The concept of energy is one of the most important topics in science Every physical.
7.4) Kinetic Energy andThe Work-Kinetic Energy Theorem Figure (7.13) - a particle of mass m moving to the right under the action of a constant net force.
Conservation of Energy
Chapters 7, 8 Energy. What is energy? Energy - is a fundamental, basic notion in physics Energy is a scalar, describing state of an object or a system.
Chapter 7 Energy of a System.
332 – UNIT 6 WORK & ENERGY.
Lecture 12: Elastic Potential Energy & Energy Conservation.
Work is the bridge between Force and Energy. The General Work Equation  W = F  r cos   F: force (N)   r : displacement (m)   : angle between.
Chapter 11: Harmonic Motion
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.
1 Chapter 6 Energy and Energy Transfer 2 3 Introduction to Energy The concept of energy is one of the most important topics in science Every physical.
Chapter 7 Conservation of Energy Conservative force Non-conservative force potential energy & potential function March 2, 2010.
Work Done by a Constant Force The work done by a constant force is defined as the distance moved multiplied by the component of the force in the direction.
Energy Notes Energy is one of the most important concepts in science. An object has energy if it can produce a change in itself or in its surroundings.
Simple Harmonic Motion  Simple Harmonic Motion – Vibration about an equilibrium position in which a restoring force is proportional to the displacement.
Conservative and Nonconservative Forces. A Force is “Conservative” if: The work it does on an object is available for kinetic energy. These forces store.
Phys211C6 p1 Work: a measure of the change produced by a force Work = force through the displacement W = F s(assuming force is constant!) Units: 1 Newton.
Simple Harmonic Motion & Elasticity
Work and Kinetic Energy
1a. Positive and negative work
November 29th If a total distance of 750 m is covered in a time interval of 25s, the average speed is ______? a.  3, 974 mph b.  3 mph c.  30 mph d.  30.
Aim: How do we characterize elastic potential energy?
Lecture Outline Chapter 7 Physics, 4th Edition James S. Walker
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.
Last Time: Work, Kinetic Energy, Work-Energy Theorem Today:
Chapter 6 Energy and Oscillations
Simple Harmonic Motion and Wave Interactions
Presentation transcript:

Potential Energy and Energy Conservation Chapter 7 Potential Energy and Energy Conservation

Potential Energy Work done by gravity: W=mg (Y2-Y1)

Work done moving up Work done by hand/normal force against gravity: W=mg (Y2-Y1) (If no acceleration) The work by you turns into work by gravity then KE

Potential energy: The energy available to “do damage” Back to swing story: A 100kg boy swings from a tire swing of Length 3[m]. The angle at the beginning is 53 degrees. a. What is the speed at the bottom? b. What is the tension in the string?

Add Elastic Energy As shown last week: When x is positive (spring is stretched), F is negative When x is 0 (at the equilibrium position), F is 0 When x is negative (spring is compressed), F is positive

Hooke’s Law The force exerted by the spring is always directed opposite to the displacement from equilibrium F is called the restoring force If the block is released it will oscillate back and forth between –x and x

Work Done by a Spring Identify the block as the system Calculate the work as the block moves from xi = - xmax to xf = 0 The total work done as the block moves from –xmax to xmax is zero

Spring with an Applied Force Suppose an external agent, Fapp, stretches the spring The applied force is equal and opposite to the spring force Fapp = -Fs = -(-kx) = kx Work done by Fapp is equal to ½ kx2max

Energy bar diagram, problem 2 A block of mass m=5[kg] is sliding 11[m] down a frictionless inclined plane, inclination 37 degrees. It then hits a spring with K=800 [N/m] spring constant. How many meters would the spring be compressed?

Instantaneous Power The instantaneous power is the limiting value of the average power as Dt approaches zero This can also be written as

Units of Power The SI unit of power is called the watt 1 watt = 1 joule / second = 1 kg . m2 / s2 A unit of power in the US Customary system is horsepower 1 hp = 746 W Units of power can also be used to express units of work or energy 1 kWh = (1000 W)(3600 s) = 3.6 x106 J

Example A 50.0 kg marathon runner runs up the stairs to the top of Chicago’s 443-m-tall Sears Tower, the tallest building in the United States. To lift herself to the top in 15 minutes, what must be her average power output in watts? In kilowatts? In horsepower?

Feedback: Privacy Policy Feedback
Do Not Sell My Personal Information
About project: SlidePlayer Terms of Service

© 2025 SlidePlayer.com. Inc. All rights reserved.