ENERGY EQUATIONS By the end of this presentation you should be able to: Calculate kinetic energy, work and power.

Slides:

Advertisements

Similar presentations

Chapter 5 Work, Energy and Power

Advertisements

Ch 8 Energy Notes ENERGY.

Practice Problem #1 A weightlifter bench presses 80kg (approx. 175lbs.) 0.75m straight up. a. How much work does she do, assuming constant velocity, in.

Work and Energy By Mr Leavings Chapter 5. What is Work In science Work has a specific meaning. If you push a box with a force of one newton for a distance.

Work, potential and kinetic energy

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.

Fall Final Review WKS: WORD PROBLEMS. Average Speed 1. A rock is dropped from the top of a tall cliff 9 meters above the ground. The ball falls freely.

Power The rate at which work is done. Objective: To define and apply the concepts of power and mechanical efficiency.

What is an instrument that makes work easier called?

Chapter 5 Section 1: What is Energy?

Mechanical Work: More Practice. Gravitational Potential Energy: More Practice.

Simple Machines As well as Work Efficiency and Mechanical advantage.

Mathematically we define power as: The unit of power is J/s or Watts (W) (this is sometimes confusing because W is also the symbol for work) Mathematically.

Elastic Potential Energy: More Practice. Conservation of Mechanical Energy: Learning Goal The student will investigate a simple energy transformation,

The apple is ……. Vel ocity = = = x x  :. The apple is ……. = =  : x x =x.

Chapter 4 Work & Energy Dr. Ali.

Work, Power, and Machines

ENERGY The measure of the ability to do work Conservation of energy -energy can change forms but can not be destroyed -the total amount of energy in the.

How much work does a 154 lb. student do when climbing a flight of stairs that are 6 meters in height and 30 meters in length? If the stairs are climbed.

Let us now look at the work done by a net force.  = 0 o, so cos  = 1 Maximum kinetic energy that an object can have. Change in kinetic energy due to.

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)

Chapter 10 & 11 Energy & Work. Energy The capacity of a physical system to perform work. Can be heat, kinetic or mechanical energy, light, potential energy,

CHAPTER 10 WORK, ENERGY, AND POWER. STANDARDS SP3. Students will evaluate the forms and transformations of energy. a. Analyze, evaluate, and apply the.

Warm up 1) How much energy does a 45 kg rock have when it is at the top of a 70 m cliff? 2) How much energy does a 20 kg tricycle have when it is moving.

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

Applied Physics Chap 4 Energy1 Chapter 8: Energy The universe is composed of two substances called matter and energy which are interrelated on some fundamental.

Simple Machines. Example A frictionless 30 o ramp is used to lift a 500kg crate up a vertical distance of 1.5m. If the ramp is used is 4.0m long, a) What.

WORK AND SIMPLE MACHINES. WORK Work is said to be done when a force acting on a body moves the body a certain distance in the direction of the force when.

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 Energy Energy Universe is made up of matter and energy. Energy is the mover of matter. Energy has several forms: –Kinetic, Potential, Electrical,

Chapter 13 WORK & ENERGY. TN Standards CLE – Demonstrate the relationship among work, power, and machines CLE – Investigate the Law.

Ch. 8 Energy. Learning Intention Understand how to describe, discuss, and quantify the energy of a system Journal: Why do you think this concept is important?

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.

Jeopardy This iS Energy Energy Vocabulary Potential & Kinetic Energy.

Section 4 Conservation of Energy. I. Energy Transformations PE = mgh PE = (515 kg)(9.8 m/s 2 )(70.0 m) PE = 353,290 J At the top of the hill, PE is at.

Energy, Work and Power. Work, Energy and Power Objectives: Describe the relationship between work and energy Calculate the work done by a constant applied.

Aim: How can we apply work- energy to motion problems? Do Now: In your own words, what does energy mean to you? In your own words, what does energy mean.

Work = work is done when a net force on an object causes it to move a distance W = Fd Or Work (measured in joules) = Force (N) times Distance (m) Is work.

In this section you will use the equation to calculate work done use the equation to calculate kinetic energy solve simple energy interchange problems.

Unit 5: Work, Power and Energy. Work Work is done when a force causes a change in motion of an object, or work is a force that is applied to an object.

Physics Section 5.4 Define “power” Power- is the rate at which work is done or energy is transformed. P = W ∆t P = power (watts) W = work (J) t = time.

Work is only done by a force on an

As well as Work Efficiency and Mechanical advantage

Chapter 8: Energy.

Conservation of Mechanical Energy: Learning Goal

Conservation of Energy

Efficiency and Simple Machines

Rearranging equations

Tue Jan 31 Today Review hw 5. 5 Read p (p280) 83,87,91

Topic: Kinetic and Potential Energy

Tue Jan 31 Today Review hw 5. 5 Read p (p280) 83,87,91

EQUATIONS P2 Topic 4: Momentum, energy, work and power

IS Jeopardy Work Power Energy Misc Potpourri

No work Calculating Work Machines affect on work

EQUATIONS P2 Topic 4: Momentum, energy, work and power

Work, potential and kinetic energy

Changes in energy stores

1 Changes in energy stores List the different types of energy

Chapter 13 WORK & ENERGY.

Reviewing Main Ideas Work

Do Now: 02/19/2014 What type of simple machines are shown below:

EQUATIONS P2 Topic 4: Momentum, energy, work and power

Work, Energy and Power.

Chapter 8 – Hewitt Review Questions

Objectives Define work in terms of energy.

Work, energy and power.

Presentation transcript:

ENERGY EQUATIONS By the end of this presentation you should be able to: Calculate kinetic energy, work and power.

Energy Equations Mechanical energy _________ energy is the energy an object has because of its speed (or _________ ). The faster it is moving, the _________ its _________ energy will be. KINETIC VELOCITY GREATER KINETIC KINETIC ENERGY (KE) = 1 x m x v2 2 Where m= mass (kg) , v = speed or velocity (m/s)

Question 1 How much kinetic energy does this car have? Mass = 2000 kg Velocity = 40m/s Mass = 2000 kg Since k.e. = ½ mv2, then k.e. = ½ x 2000 x 40 x 40 So the car has 1 600 000J of kinetic energy (1600kJ)

The remaining equations The equations (and the units used for all the quantities) to calculate… Work done = Power = Force x distance J N m Energy transformed / time W J s

Work done question 5 Calculate how much work is done in pushing the crate with a force of 40N up the ramp. W = F x d = 40 x 5 = 200J 5m 40N

Work done question 6 Calculate how much work is done in lifting the crate, if its weight is 45N, to the top of the ramp (4m high). W = F x d = 45 x 4 = 180J The ramp supports some of the weight of the crate so allows a person to move it with a force smaller than the total weight, but the length of the ramp is greater than its height so more work is done using the ramp. The ramp does make the job easier however! Energy is also wasted while pushing the crate up the ramp due to friction. 4m 45N

Power and efficiency qu 7 and 8 The same crate is lifted to the top by an electric motor and pulley. It takes 20 seconds to do the job (180J of work). What is the power output of the motor? P = W / t = 180 / 20 = 9W (watts) The electric motor is actually rated at 15W (this means it is taking in 15J of electrical energy every second). What is the efficiency of this motor? 4m Efficiency = power output = 9 power input 15 = 0.6 = 60% 45N