Chapter 5 – Work, Power, & Machines “Give me a lever and a place to stand and I will move the earth.” Archimedes.

Slides:



Advertisements
Similar presentations
Work in Science.
Advertisements

Work and Simple Machines 1. What is work? In science, the word work has a different meaning than you may be familiar with. Work: using a force to move.
WHAT IS FRICTION?. WHAT IS FRICTION? WHAT IS FRICTION? Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material.
1 Work and Simple Machines. Work Answer the following questions with your elbow partner.  What is work?  Does everyone do work?  We are going to contrast.
Unit 3 Work, Power, and Machines
Definitions: Energy: Work= Force: Ability to do work Force x Distance
WORK.
Work and Simple Machines
Work and Power Chapter 5!! The End of the ROAD is near…..!!
1 Work in Science. 2 What is work?  In science, the word work has a different meaning than you may be familiar with.  The scientific definition of work.
Work. What is work? In science, the word work has a different meaning than you may be familiar with. The scientific definition of work is: using a force.
Chapter 8 Work. Terms to Learn Work - the action that results when a force causes an object to move in the direction of the force being applied and only.
Force, Work, and Power.
 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? 
Unit 3 Work, Power, and Machines
1 Work and Power. 2 What is work?  Definition: energy transferred by a _____________ to move an object a _____________ (when both the force and the motion.
1 Work and Simple Machines 2 What is work?  In science, the word work has a different meaning than you may be familiar with.  The scientific definition.
Work and Simple Machines
Work and Simple Machines
Work and Power.
Simple Machines Work and Simple Machines What is a Simple Machine?  A simple machine has few or no moving parts.  Simple machines make work easier.
1.  Read each slide carefully.  Record notes on notebook paper.  Give your notes a title: “Work Notes”  Write the title of each page in which you.
P. Sci. Unit 3 Work, Power, and Machines SPS8: Students will determine relationships among force, mass, and motion. SPS8.e: Calculate amounts of work and.
Force, Work, and Power. Net Force Practice Problems 1. A 1200kg truck that is traveling at 50 m/s 2 has a head- on collision with a 400kg car that is.
1 Work and Power. 2 History of Work Before engines and motors were invented, people had to do things like lifting or pushing heavy loads by hand. Using.
Simple Machines Work and Simple Machines What is a Simple Machine?  A simple machine has few or no moving parts.  Simple machines make work easier.
The weight lifter applies a large force to hold the barbell over his head. Because the barbell is motionless, no work is done on the barbell.
Work, Energy, and Power.
1 Work and Simple Machines. 2 What is work?  In science, the word work has a different meaning than you may be familiar with.  The scientific definition.
Work and Simple Machines. Work When a force causes an object to move – work is done. When a force causes an object to move – work is done.
 Energy, Work and Simple Machines  Chapter 10  Physics.
SPS8.e. Calculate amounts of work and mechanical advantage using simple machines.
What is Work?. Work Demo One student pushes against the wall. One student pulls up a set of keys Who does more work? Why? Who was applying more force?
A force of 15 newtons is used to push a box along the floor a distance of 3 meters. How much work was done in this situation?
They keep us grounded.  A force is simply a push or a pull.  F = ma (mass x acceleration)  Forces are measured in Newtons  Force has direction (whichever.
1 Work and Intro to Energy. OPENER: ( 5 min) 1. Turn to the next available page in your journal 2. Write the date: 3. Write the word ENERGY in LARGE letters.
1. What is work? In science, the word work has a different meaning than you may be familiar with. The scientific definition of work is: using a force.
Work.
Potential and Kinetic Energy Energy! All objects need energy to move! unit is Joules (J) Objects must store energy to be able to move later You store.
1.A machine________________ the amount of work you do. A. DecreasesC. Increases B. Does not changeD. Divides Does not change.
Understanding and Calculating Work Work - When a force acts on an object and causes it to move through a distance, energy is transferred and work is done.
Work, Power, and Energy. WORK  In Physics, work has a very specific definition.  This is not work in Physics.
1. In science, the word work has a different meaning than you may be familiar with. Work: using a force to move an object a distance 2.
Work and Simple Machines 1. Warm Up – copy the objective What is work? Open textbook to page
STARTER WHAT ARE THE SIX SIMPLE MACHINES? WHY DO WE USE SIMPLE MACHINES? WHAT IS THE EFFORT FORCE AND RESISTANCE FORCE? WHAT IS MECHANICAL ADVANTAGE?
Work and Simple Machines
Work and Power.
Unit 5: Work, Power, Simple Machines and Energy
Work.
Unit 8-4 & 8-5 Work and Machines
Ch. 5 – Work & Machines I. Work A. Work:
Chapter 5 – Work, Power, & Machines
Today’s Agenda… Bellringer: What conditions have to be met for something to be considered work? Discuss Homework Notes on Work and Machines Simple Machines.
St. 15, 16, 17: Work, Power, and Simple Machines
Chapter 5 – Work, Power, & Machines
Work.
Work and Power.
Work and Power.
Write a response to this question in your own words.
Objectives: Learning Intentions – Success Criteria –
Chapter 5 – Work, Power, & Machines
Work and Power.
Unit 8-4 & 8-5 Work and Machines
Work and Machines Review
Today we will: Learn what “work” is! Learn how to calculate work
Potential & Kinetic Energy
Work.
Work and Simple Machines
Science 9 Chapter 5: Work and Machines Chapter 6: Thermal Energy
Work and Simple Machines
Presentation transcript:

Chapter 5 – Work, Power, & Machines “Give me a lever and a place to stand and I will move the earth.” Archimedes

WORK Work: Transfer of Energy that occurs when a force makes an object move. NOT every force results in work –The direction of the force and the motion of the object must be taken into account 2 conditions for work to happen –Object must move –Force and movement are in the same direction W = F × d Work (J) = Force (N) × Displacement (m) × cosө F = ma

Examples of work –a soccer player kicking a goal –a pitcher throwing in the first pitch –a student lifting a backpack full of books upon her shoulder –a father picking up a child off the floor –a track star launching the shot-put The force exerted on the object and its motion are in the same direction.

Is this really work? Draw force vector & motion vector to verify answer. A body builder lifts 350 pounds above his head. A mother carries her baby from room to room. Busy mom pushes a grocery cart. A woman carries a 20 kg grocery bag to her car? Yes No Yes No

Work Example Problem A crate is moved across a frictionless floor by a rope. The tension in the rope is 50 N. How much work is done in moving the crate 10 m?

Power Power: the rate at which work is done. P = W/TSI unit: Watt (W) Power (W) = Work (J) Time (sec) work and power

Example Problem: Work & Power 2 soccer players work out in the off season by sprinting up a 100-m hill before stopping, resting, and walking back down. Mia and Julia weigh the same, 588N. It takes Mia 42 sec and Julie 38 sec to reach the top of the hill. A.Which athlete did more work? B.Which athlete produced more power?

Bill Nye – Simple Machines sXM58&feature=relmfuhttp:// sXM58&feature=relmfu