Kinetic and Potential Energy

Slides:



Advertisements
Similar presentations
AP Physics B Summer Course 年AP物理B暑假班
Advertisements

Chapter 5 Energy 1. Dot product of vectors 2. Kinetic Energy 3. Potential Energy 4. Work-Energy Theorem 5. Conservative and non-conservative forces 6.
Work, Energy, And Power m Honors Physics Lecture Notes.
9 Energy Energy can change from one form to another without a net loss or gain.
DEFINITION OF KINETIC ENERGY Kinetic energy is the energy of motion
Conservative Forces Lecturer: Professor Stephen T. Thornton
Energy Chapter 4.
WORK, ENERGY, POWER. Types (and changes) of Energy.
Energy.
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.
CONSERVATION OF MECHANICAL ENERGY
Work is only done by a force on an object if the force causes the object to move in the direction of the force. Objects that are at rest may have many.
WORK In order for work to be done, three things are necessary:
Energy the ability (capacity) to do work Energy comes in many forms: mechanical, electrical, magnetic, solar, thermal, chemical, etc... thermal, chemical,
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,
Herriman High Honors Physics Chapter 5 Work, Power and Energy What You Need to Know.
Work Kinetic Energy Potential Energy. Work is done when There is an application of a force There is movement of something by that force Work = force x.
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.
Unit 5 – Lecture 1. Energy Energy – the ability to do work the ability to cause change measured in joules symbol: [as in.. E = mc 2 ] E.
Physics Chapter 11 Energy.
Energy and Conservation Physics Chapter 5-2 (p ) Chapter 5-3 (p )
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.
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.
Energy and Power.
Work IN, Work OUT The Work/Energy Principle. Kinetic Energy KE depends on mass and velocity Work done on an object will change KE.
Hooke’s Law and Elastic Potential Energy
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)
Work and Energy Energy Chapter 5: Section 2. Learning Targets Identify several forms of energy Calculate kinetic energy for an object Distinguish between.
Work has a specific definition in physics. Work is done anytime a force is applied through a distance.
Sub title Potential Energy Work Work- Energy Theorem Kinetic Energy Power 200 Work-Power-Energy.
Chapter 6 Work and Energy. Units of Chapter 6 Work Done by a Constant Force Work Done by a Varying Force Kinetic Energy, and the Work-Energy Principle.
NAZARIN B. NORDIN What you will learn: Define work, power and energy Potential energy Kinetic energy Work-energy principle Conservation.
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.
Energy The ability to do work. Kinetic Energy (KE) The energy that an object has due to its motion. KE = ½ m v 2 –KE  m and KE  v 2 –Kinetic energy.
Motion, Forces and Energy Lecture 7: Potential Energy & Conservation The name potential energy implies that the object in question has the capability of.
Work is only done by a force on an
Instructions for using this template. Remember this is Jeopardy, so where I have written “Answer” this is the prompt the students will see, and where.
Work and Energy x Work and Energy 06.
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.
Lecture 12: Elastic Potential Energy & Energy Conservation.
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 and Kinetic Energy. What is kinetic energy?  If an object is moving, it has energy. You can think of kinetic energy as the energy of motion, and.
Work and Energy Physics 1. The Purpose of a Force  The application of a force on an object is done with the goal of changing the motion of the object.
Conservation of Energy
Examples: Mechanical Energy Conservation
Work, Power & Energy How do they relate? (Stone, Ebener, Watkins)
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. Mechanical Energy  Mechanical Energy is the energy that an object has due to its motion or its position.  Two kinds of mechanical.
Work is only done by a force on an object if the force causes the object to move in the direction of the force. Objects that are at rest may have many.
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.
Energy, Work and Power. Work, Energy and Power Objectives: Describe the relationship between work and energy Calculate the work done by a constant applied.
Work and Energy 1 st Law of Thermodynamics  Energy cannot be created or destroyed. It can only be converted from one form into another.
Work is only done by a force on an object if the force causes the object to move in the direction of the force. Objects that are at rest may have many.
Chapter 6 Work and Energy © 2014 Pearson Education, Inc. No need to write information in red.
Work Power Energy. Work Concepts Work (W) ~ product of the force exerted on an object and distance the object moves in the direction of the force. Work.
Energy. Energy Energy (def.) the ability to do work. Unit is Joules. Work and energy are interrelated. Work must be done on an object to get it to.
Let’s Play! Please listen carefully and think before answering.
Chapter 5 Work and Energy
BELLWORK 2/01/17 From the work-kinetic energy theorem, we see that the speed of an object ______ if the net work done on it positive, because the final.
Work and Energy Energy.
Energy comes in many forms: mechanical, electrical , magnetic, solar,
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.
Mechanical Energy.
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.
Unit 5 ENERGY.
Energy.
Presentation transcript:

Kinetic and Potential Energy Conservation of Energy

Kinetic Energy kinetic energy - the energy objects have because they are in motion m –mass of object (kg) v – velocity of object (m/s) Like work, the unit of energy is the joule (J)

Example A 1400 kg car is travelling at 30 m/s. What is its kinetic energy?

Work-Energy Theorem An important relationship can be found between work and kinetic energy. It is known as the work-energy theorem, “the change in an object's kinetic energy is equal to the net work done on the object.”

Example pool cue strikes a ball of mass 0.25 kg and gives it a speed of 1.5 m/s. If the force exerted by the cue is 20 N, over what distance did this force act?

Example 2 A soccer player kicks a soccer ball initially at rest. She exerts a force of 500 N on the ball over a distance of 10 cm. If the ball has a mass of 450 kg, with what speed does it leave her foot?

Potential Energy Potential energy - energy an object has because of its position or state. (stored work) Use the symbol U to represent potential energy. A battery contains chemical potential energy and when that energy is released, it can do work to power your walkman, etc.

Gravitational Potential Energy The potential energy used most often in physics is gravitational potential energy. When you lift a bowling ball, you must do work against gravity. That work is transformed into gravitational potential energy which can be released as kinetic energy if you drop the ball.

Formula for PE To eliminate the choosing of a reference point we talk about change in potential energy

Example What is the increase in the gravitational energy of a 5 kg book that is lifted from the floor to a table 1.5 m high?

Example 2 A falling ball of mass 250 g losses 25 J of gravitational potential energy. What distance has the ball fallen?

Potential Energy of a Spring You can also store potential energy in a spring. The formula for this is: Us = ½kx2 Notice that it's the same formula as the work done by a spring. Also notice that spring potential energy is always positive.

Example A spring has a spring constant of 800 N/m. How much must this string be stretched to store 75 J of potential energy?

Displacement and PE

Energy and Conservation One of the most fundamental and powerful ideas in physics is the one of energy conservation. the total mechanical energy of a system is conserved. That is, the energy it initially has must be equal to its final energy. mechanical energy-the sum of its kinetic and potential energies.

Energy Conservation You can write the conservation of energy statement in many different mathematical forms. Here are some of them: KEi + PEi = KEf + PEf

Example A biologist uses a spring-loaded gun to shoot tranquilizer darts into a wild African hamster. The spring in the gun has a spring constant of 940 N/m. A 38 g dart is loaded into the gun and the spring is compressed a distance of 25 cm. With what speed will the dart leave the gun?