Work (Pay special attention to words in BLACK) What is “Work”? According to physics… Work is a force applied for a certain distance. W=F  x.

Slides:

Advertisements

Similar presentations

Unit 5-2: Energy. Mechanical Energy When mechanical work is done, mechanical energy is put into or taken out of an object. Mechanical energy is a measurement.

Advertisements

Energy Chapter 5 Section 2. What is Energy? Energy – A scalar quantity that is often understood as the ability for a physical system to produce changes.

Conservation of Energy Energy is Conserved!. The total energy (in all forms) in a “closed” system remains constant The total energy (in all forms) in.

Springs And pendula, and energy. Spring Constants SpringkUnits Small Spring Long Spring Medium spring 2 in series 2 in parallel 3 in series 3 in parallel.

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.

Simple Harmonic Motion & Elasticity

Kinetic Energy Kinetic energy is energy of motion. Kinetic energy is a scalar quantity. KE = ½ mv 2 kinetic energy = ½ mass x (speed) 2 Units for KE are.

Springs And pendula, and energy. Harmonic Motion Pendula and springs are examples of things that go through simple harmonic motion. Simple harmonic motion.

It takes work to lift a mass against the pull (force) of gravity The force of gravity is m·g, where m is the mass, and g is the gravitational acceleration.

Kinetic and Potential Energy Notes Chapter 5-2. Mechanical Kinetic Energy Amount of energy an object has based on motion Depends on the mass of the object.

Power and Energy. James Joule British physicist James Joule is best known for his work in electricity and thermodynamics Together with the physicist William.

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.

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.

Physics Chapter 11 Energy.

Energy and Conservation Physics Chapter 5-2 (p ) Chapter 5-3 (p )

Section 2: Kinetic Energy & Potential Energy Lockheed Martin completes final test flight of its hyper-velocity kinetic weapon.

Kinetic and Potential 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.

Energy Chapter 5 Section 2.

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.

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.

Unit 07 “Work, Power, Energy and Energy Conservation” The Conservation of Mechanical Energy Kinetic and Potential Energy.

Review and then some…. Work & Energy Conservative, Non-conservative, and non-constant Forces.

Mechanical Energy. Kinetic Energy, E k Kinetic energy is the energy of an object in motion. E k = ½ mv 2 Where E k is the kinetic energy measured in J.

Work and Energy. Work a force that causes a displacement of an object does work on the object W = Fdnewtons times meters (N·m) or joules (J)

Energy Chapter 7.

Work has a specific definition in physics. Work is done anytime a force is applied through a distance.

Energy and Energy Conservation. Energy Two types of Energy: 1. Kinetic Energy (KE) - energy of an object due to its motion 2. Potential Energy (PE) -

Review work and energy Physics. What is the law of conservation of energy? What does it mean for this unit?

Warm up 1. A 500 kg car is traveling 18 m/s, how much kinetic energy does it have (in Joules)? 1. A 500 kg car is traveling 18 m/s, how much kinetic energy.

Ch. 6, Work & Energy, Continued. Summary So Far Work-Energy Theorem: W net = (½)m(v 2 ) 2 - (½)m(v 1 ) 2   KE Total work done by ALL forces! Kinetic.

WORK A force that causes a displacement of an object does work on the object. W = F d Work is done –if the object the work is done on moves due to the.

Work, Power & Energy How do they relate? (Stone, Ebener, Watkins)

ENERGY Objectives: After completing this module, you should be able to: Define kinetic energy and potential energy, along with the appropriate units.

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.

CHAPTER 5 Work and Energy Work: Work:Work done by an agent exerting a constant force is defined as the product of the component of the force in the direction.

Work and Energy Energy. Kinetic Energy Kinetic energy – energy of an object due to its motion Kinetic energy depends on speed and mass Kinetic energy.

Energy – the ability to do work W = Fd = m a d V f 2 = V i 2 + 2a  x V f 2 - V i 2 = + 2a  x V f 2 - V i 2 = a  x 2.

1 PPMF102 – Lecture 2 Work & Energy. 2 Work = force x displacement x cos  Work = force x displacement x cos  W = Fs cos  W = Fs cos  Scalar quantity.

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.

Work and Energy 1 st Law of Thermodynamics  Energy cannot be created or destroyed. It can only be converted from one form into another.

Conservation of Energy (a.k.a Slacker Physics). Now, Really…Conservation of Energy In a system, energy can not be created or destroyed. Energy can change.

Energy and its Conservation Physics Mrs. Coyle. Part I Mechanical Energy – Potential – Kinetic Work Energy Theorem.

Work and Energy Chapter 5. Work In physics: “the amount of energy transferred from one object to another” Measured in Joules (J) Mathematically: W = Fd.

Energy and Work. Work… Work = Force // x Displacement W = F // x d ** Remember that displacement is the distance AND direction that something moves. It.

Simple Harmonic Motion & Elasticity

Unit 7: Work, Power, and Mechanical Energy.

Springs And pendula, and energy.

Chapter 6 Power and Energy

Work & Energy w/o Machines

Kinetic and Potential Energy

Chapter 5.2 Notes Potential Energy.

Chapter 5.3 Review.

Conservation of Energy with Springs AP style

Let’s Play! Please listen carefully and think before answering.

Potential and Kinetic Energy

Section 2: Kinetic Energy & Potential Energy

Work-Energy Theorem Energy is the ability to do work.

Work and Energy Energy.

Energy comes in many forms: mechanical, electrical , magnetic, solar,

Work and Energy.

Mechanical Energy, Me (Units of joules (J))

Chapter 5 Review.

PE, KE Examples Answers 1. A shotput has a mass of 7.0 kg. Find the potential energy of a shotput raised to a height of 1.8 m. m = 7.0 kg h.

Science that goes boing AP Physics Part 1

Chapter 5.2 Review.

Ch 4 Energy Kinetic Energy (KE) – the energy a moving object has because of its motion; depends on mass and speed of object KE = mv2/2 Joule – SI unit.

Ch 8 Energy Notes ENERGY – 5.2 PPT.

GRAVITATIONAL POTENTIAL & KINETIC ENERGY

Presentation transcript:

Work (Pay special attention to words in BLACK) What is “Work”? According to physics… Work is a force applied for a certain distance. W=F  x

Work A 50 Kg car is moved 40 m by a 30 N force. How much work is done to the car? 1200 Nm 1Nm = 1 Joule = 1 J So, W = 1200 J

W = F  x = ma  x But, V f 2 =V i 2 +2a  x Rearrange: a  x= (V f 2 -V i 2 )/2 Substitute: W= ma  x = m (V f 2 -V i 2 )/2 So: W = 1/2m V f 2 -1/2mV i 2 1/2mv 2 has a special name: Kinetic Energy!

Kinetic Energy Kinetic energy is another way that physics looks at motion: KE = 1/2mv 2 Looking back… W=  KE So: Work is the change in Kinetic Energy.

Kinetic Energy Reconsidering the car problem: If the 50 Kg car began at rest and experienced 1200 J of work how fast is the car traveling after the work is done? V f =6.9 m/s

Potential Energy Potential energy is anything that has the potential to do work to an object. A rock on top of a hill, a stretched slingshot, a hydrogen/Oxygen mixture etc. (What types of potential energy are each of the examples?)

Gravitational Potential Energy: PEg = mgh m = mass, g = 9.8 m/s 2, h = height

Gravitational Sample A 2000 Kg boulder sits 43m above the ground on top another larger boulder. What is the potential energy of the top boulder? PEg = 842,800 J

Elastic Potential Energy PEe= 1/2kx 2 k = spring constant = F/x (Hooke’s Law) X= displacement from the relaxed position F = Force

A 45 Kg block is against a spring with spring constant 950 N/m. The spring is compressed 10 cm from the relaxed position. How much energy is stored in the spring? PEe = 4.8 J

Conservation of Energy Energy cannot be created nor destroyed. The total mechanical energy initially must equal the total mechanical energy finally.  MEi =  MEf KE i +PEg i + PEe i = KE f + PEg f + PEe f

Conservation of Energy KE i +PEg i + PEe i = KE f + PEg f + PEe f KE is the Energy of “MOVING” PEg is the energy of “UP” PEe is the energy in a “SPRING” Moving?Up?Spring? Moving?Up?

A 2000 Kg boulder sits 43m above the ground on top another larger boulder. It falls! How fast is the boulder moving just before hitting the ground? V f = 29 m/s

A spring with a spring constant of 35 N/m is compressed 0.23 m from its relaxed position. Resting against this spring is a 0.08 Kg character. When the character is released, what is his maximum velocity? 4.8 m/s

Pendulum A pendulum has a 5.0 Kg mass attached to a 1.2 m long string. If the pendulum is brought back through an angle of 25 o, what will the maximum velocity be? 1.4 m/s