Section 1: Work, Power, and Machines

Slides:



Advertisements
Similar presentations
Work, Power, and Machines
Advertisements

Chapter 13: Work and Energy
WORK and POWER!.
Section 1 Work, Power, and Machines
13-Work and Energy 1-Work, Power, and Machines Work: The transfer of energy to an Object by the application of force that Causes the object to move in.
Work and machines Machines make jobs easier. Machine – a device that helps do work by either changing the size of a force or changing the direction of.
Notes on Chapter 8 Work & Energy
The Meaning of Work And Types of Energy. Types of Energy Kinetic Kinetic energy is energy in the form of motion A moving hockey puck has kinetic energy.
 Write a list of 10 examples your idea of work.  What do all of these have in common?  What do they require?  How do you assess if work is done? 
Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Work, Power, and Machines Objectives Define work and power.
Ch 9 What is Work ? What is the equation for work?
Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Work, Power, and Machines Objectives Define work and power.
Work, Power & Mechanical Advantage. What is Work?? Work is only done when a force causes a change in the position or the motion of an object The motion.
Section 1Work and Energy Chapter 13. Section 1Work and Energy What Is Work? 〉 How is work calculated? 〉 Work is calculated by multiplying the force by.
Section 1Work and Energy EQ: How are work and mechanical advantage of simple machines calculated?
SPS8.e. Calculate amounts of work and mechanical advantage using simple machines.
WHAT IS WORK?  transfer of energy to a body by application of a force that causes body to move in direction of force.  W = F  d SI units:  joules.
Section 1Work and Energy Section 1: Work, Power, and Machines EQ: What is the relationship between work and power?
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?
Power. Rate of Energy Transfer  Power is a quantity that measures the rate at which work is done or energy is transformed. P = W / ∆t power = work ÷
WHAT IS WORK?. Work when you exert a force on an object that causes the object to move some distance Work is done when the object moves in the same direction.
Section 1Work and Energy Section 1: Work, Power, and Machines Preview Key Ideas Bellringer What Is Work? Math Skills Power Machines and Mechanical Advantage.
Section 1 Work, Power, and Machines Objectives Define work and power. Calculate the work done on an object and the rate at which work is done. Use the.
Bellringer #51 Read “Careers Using Physics” on page 427 Read “Careers Using Physics” on page 427 Answer both questions in your journal Answer both questions.
Work, Power, & Simple Machines Assistance from Derek Hinrichs.
TABLE OF CONTENTS SECTION 1 : WORK, POWER, AND MACHINES SECTION 2 : SIMPLE MACHINES SECTION 3 : WHAT IS ENERGY? SECTION 4 : CONSERVATION OF ENERGY Chapter.
12.1 Work I can: -recognize force and displacement must be in the same direction for work to be done. -use the equation w=f x d to calculate work.
Today’s lesson Learn what “work” is! Learn how to calculate work
Tue Jan 31 Today Review hw 5. 5 Read p (p280) 83,87,91
Energy Physics.
Work, Power, and Efficiency
Section 1: Work, Power, and Machines
Section 1: Work, Power, and Machines
ENERGY EQUATIONS By the end of this presentation you should be able to: Calculate kinetic energy, work and power.
Tue Jan 31 Today Review hw 5. 5 Read p (p280) 83,87,91
Work, Power & Energy.
Chapter 13: Work and Energy Physical Science Coach Mynhier.
WORK, POWER, & EFFICIENCY
Work, Impulse, Momentum and Power
Section 1: Work, Power, and Machines
What machines do for us.
St. 15, 16, 17: Work, Power, and Simple Machines
How much work is done when a boy carries a 30N bag?
Section 1: Work, Power, and Machines
Goal 7  Students will solve for work in the equation work = force X distance and will recognize that force and distance must act in the same direction.
Chapter 12, Section 1: What is work?
Chapter 12 Work and Energy
10.2 Work 1.
Section 3: Newton’s Third Law
Bell Ringer What does the word work mean to you?
Part 1: Work, Power, & Machines
Work Power and Machines
November 19, 2015 How would you define “work” in your own words?
April 20, 2010 Explain why holding a large box is not considered work.
Work, power, and machines
Mechanical Advantage Simple Machines.
& Power.
Mechanical Advantage Simple Machines.
Chapter 12 Work and Energy
Work and Mechanical Advantage
Goal 7 Work and Mechanical Advantage
Mechanical Advantage Simple Machines.
What is work Chapter 4 section 1.
Work and Simple Machines
Work, Power, and Machines
WORK and POWER!.
Section 1: Work, Power, and Machines
Science 9 Chapter 5: Work and Machines Chapter 6: Thermal Energy
Simple Machines & Work.
How Do Machines Work Chapter 4 Section 2.
Presentation transcript:

Section 1: Work, Power, and Machines Preview Key Ideas Bellringer What Is Work? Math Skills Power Machines and Mechanical Advantage

Key Ideas How is work calculated? What is the relationship between work and power? How do machines make work easier?

Bellringer Which of the following is an example of work: bowling or reading? a. A man pushes against a brick wall, which doesn’t move. Is this an example of work? b. A student carries her books to class. Is this an example of work? c. A woman raises and lowers dumbbells at the gym. Is this an example of work? d. A book falls off a table and lands on the floor. Is this an example of work?

What Is Work? How is work calculated? Work is calculated by multiplying the force by the distance over which the force is applied. work = force x distance, or W = Fd The force must be applied in the direction of the object’s motion.

What Is Work?, continued work: the transfer of energy to an object by the application of a force that causes the object to move in the direction of the force Work is zero when an object is not moving. Work is measured in joules (J): 1 N • m = 1 J = 1 kg • m2/s2

Visual Concept: Work

Math Skills Work Imagine a father playing with his daughter by lifting her repeatedly in the air. How much work does he do with each lift if he lifts her 2.0 m and exerts an average force of 190 N? List the given and unknown values. Given: force, F = 190 N distance, d = 2.0 m Unknown: work, W = ? J

Math Skills, continued Write the equation for work. work = force  distance W = f  d Insert the known values into the equation, and solve. W = 190 N  2.0 m = 380 N•m W = 380 J

Power What is the relationship between work and power? Power is the rate at which work is done, or how much work is done in a given amount of time.

Power, continued power: a quantity that measures the rate at which work is done or energy is transformed Power is measured in watts (W): 1 W = 1 J/s

Visual Concept: Power

Math Skills Power Lifting an elevator 18 m takes 100 kJ. If doing so takes 20 s, what is the average power of the elevator during the process? List the given and unknown values. Given: work, W = 100 kJ = 1  105 J time, t = 20 s Distance is not needed. Unknown: power, P = ? W

Math Skills, continued 2. Write the equation for power. 3. Insert the known values into the equation, and solve.

Machines and Mechanical Advantage How do machines make work easier? Machines help do work by changing the size of an input force, the direction of the force, or both.

Machines and Mechanical Advantage, continued Mechanical advantage is an important ratio. mechanical advantage: a quantity that expresses how much a machine multiplies force or distance

Math Skills Mechanical Advantage Calculate the mechanical advantage of a ramp that is 5.0 m long and 1.5 m high. List the given and unknown values. Given: input distance = 5.0 m output distance = 1.5 m Unknown: mechanical advantage = ?

Math Skills, continued 2. Write the equation for mechanical advantage. We need only the distance part of the full equation: 3. Insert the known values into the equation, and solve. mechanical advantage =