Energy
What happens when an archer draws back on a bowstring? Energy What happens when an archer draws back on a bowstring?
What happens when a spring is wound to run a clock? Energy What happens when a spring is wound to run a clock?
Energy In each of those scenarios “something” has been acquired that enables an object to do work.
What is that “something” that is acquired? Energy What is that “something” that is acquired?
Energy
Energy Energy is the ability to do work. Any object that has Energy has the ability to create force.
Energy The workings of the universe (including all of our technology) can be viewed from the perspective of energy flowing from one place to another and changing back and forth from one form to another.
Energy is measured in joules
Energy There are 5 main forms of energy 1. Mechanical energy 2. Heat energy 3. Chemical energy 4. Electromagnetic energy 5. Nuclear energy
Energy The five different forms of energy can be classified into either one of the two states: • Potential Energy- stored energy • Kinetic Energy- energy in motion
Energy Mechanical Energy is the energy due to the position of something, or the movement of something.
Energy Kinetic Energy -The energy of motion. -The more an object moves, the more kinetic energy it has.
Energy Kinetic Energy -The faster an object moves, the more kinetic energy it has.
Energy Kinetic Energy -The equation for solving for kinetic energy is KE = ½ mv2
What is the KE of a 4 kg mass at 3 m/s? (KE = ½ mv2)
Energy Potential Energy -Is the stored energy that a body possesses because of its position
Energy Potential Energy -Can be chemical energy in fuels or food. i.e. gasoline in a car, chemicals in a battery.
Energy Potential Energy -Can also be an elevated object, when it falls its PE will become KE
Energy Potential Energy -If it can make “something” happen, It has potential energy (PE)
Energy Potential Energy - Gravitational Potential Energy (GPE) is the energy that comes from how far an object is from the surface of the Earth.
Energy Potential Energy The equation for solving GPE is GPE = mgh where g = 9.8m/s2
What is the GPE of a 2 kg block 5 m above the floor? (GPE =mgh)
Energy Elastic Potential Energy – Stored energy in an object that is stretched or compresses, i.e. spring or a rubber band
Chemical Potential Energy – i.e. gasoline in a car, food you eat
The Law of Conservation of Energy states: What?
Energy The Law of Conservation of Energy states: Energy cannot be created or destroyed, energy only gets converted from one form to the other
Discussion What happens when you throw a ball up in the air? Energy Discussion What happens when you throw a ball up in the air?
Energy
Energy is almost always converted into another form of energy.
Energy One of the most common conversion is the changing of potential energy to kinetic energy or the reverse.
What does the Law of Conservation of Energy state?
Energy Energy conversions occur without a loss or gain in energy, therefore KE=PE.
The total energy never exceeds the starting energy.
How does friction play a part in the Conservation of Energy? Discussion How does friction play a part in the Conservation of Energy?