1 Energy Introduction
Jan 15, 2016
1
Energy Introduction
Energy
What do you think of when you hear this word?
What is Matter?
• Matter is anything that takes up space or has mass.
• Everything that is in this room is matter.–Desk, chairs, posters, folders, water, air
• There are four states of matter:–Solid–Liquid–Gas–Plasma
• All matter is made of atoms.
Energy
• Energy is the ability to do work on or cause change in matter.•Everything has energy!–It moves cars along the road–It’s the sound of footsteps–It’s the warming of your desktop when your hand touches it.
Energy and its Forms
• Energy is found in many different forms including:–chemical, electrical, heat/thermal, light, mechanical, nuclear, sound, etc.
• As you can see, there are many forms of energy, but they can all be put into two main categories:–Kinetic & Potential
Kinetic Energy
• Kinetic Energy- the energy of movement.–Example: A person jogging at a park.
• If something is in motion, it has kinetic energy.
• What has kinetic energy in these pictures?
Potential Energy
•An object still has energy even if its not moving.• Potential Energy- energy of position or stored energy–Ex. A glass of water sitting on the edge of a table. While sitting there it has stored energy because of its position.–If it is nudged, it can fall to the floor and has energy of motion.
Potential
Kinetic
Potential Energy• If something is not
currently in motion but has the potential to be in motion at some point, it has potential energy.• Which of these pictures
represents potential energy?
Potential Versus Kinetic Energy
• Think of all the forms of kinetic and potential energy you would see in the following situation: AT A PARK
Potential Versus Kinetic Energy
• Think of all the forms of kinetic and potential energy you would see in the following situation: AT SCHOOL
Experiment: Does mass affect potential and kinetic
energy?• Think of the following situations:–Rolling a bowling ball down the alley versus rolling a volleyball down the alley.
–Two people of different weights racing down a hill on a sled.
Experiment: Does ramp height affect potential and kinetic
energy?• Think of the following situation:–Riding a bike down Ginger Ridge Drive versus riding down the hill in the parking lot.
Energy Lab1. Question: Does mass & ramp height affect potential and kinetic energy?
2. Use What I Know
3. Hypothesis: Write one of the following sentences.
Write one of the following sentences.
4. Experiment- Materials:
Design (paragraph or picture): ramp 6 & 9 inches, finish line 5 feet away from bottom of ramp
Constants: I need to keep the following things the same in the experiment to make it fair…
I believe ramp height increases the amount of energy
an object has.
I believe ramp height decreases
the amount of energy an object
has.I believe ramp
height has no effect on the amount of energy an object
has.
I believe mass increases the
amount of energy an object has.
I believe mass decreases the
amount of energy an object has.
I believe mass has no effect on the
amount of energy an object has.
Energy Lab5. Data:Test 1- Car with no added mass, Ramp Height- 6 inchesTrial 1 Time: Trial 2 Time: Trial 3 Time:Average:Class Average:
Test 2- Car with added mass, Ramp Height- 6 inchesTrial 1 Time: Trial 2 Time: Trial 3 Time:Average:Class Average:
Test 3- Car with no added mass, Ramp Height- 9 inchesTrial 1 Time: Trial 2 Time: Trial 3 Time:Average:Class Average:
Energy Lab7. Conclusion: Based on your results, write one of the following sentences.–Mass increases the amount of energy an object has
because the car with more mass went faster.–Mass decreases the amount of energy an object has
because the car with more mass went slower.–Mass had no effect on the amount of because both cars
went the same speed.Based on your results, write one of the following sentences.–Ramp height increases the amount of energy an object
has because the car went faster on the steeper ramp.–Ramp height decreases the amount of energy an object
has because the car went slower on the steeper ramp.–Ramp height had no effect on the amount of because
both cars went the same speed.
Self Check
• Do you understand kinetic versus potential energy? Answer the questions about the energy of the ball as it rolls from point A to point G.
Being held at point A (Not in motion)
Gaining speed Losing speed
Types of EnergyTypes of Energy
Mechanical Energy-Type of Kinetic and Potential Energy
(Both)•Definition: The amount of work an object can do because of its kinetic and potential energies.
•Example: A rolling bowling ball has __________ energy (one type of mechanical energy) and the stationary pins have __________ energy (another type of mechanical energy) When the ball strikes the pins, its energy is transferred to the pins. Now both the ball and the pins have __________ energy.
•Other information:
•Mechanical Energy= Kinetic + Potential Energy
•ALL MATTER HAS MECHANICAL ENERGY
Chemical Energy-Type of Potential Energy
• Definition: Chemical energy is energy stored in the bonds of atoms and molecules.
• Examples: Batteries (Power various objects, Petroleum (Fuels our cars), Natural gas (Fuels fireplace), Coal (Fuels factories), Wood (Fuels fire), Food (Provides energy for our bodies)
• Other Information:
THINK OF FUEL
• Chemical energy is converted to other forms of energy when we burn/use these things.
• Definition: Nuclear energy is energy stored in the nucleus of an atom.
• Example: Occurs in nuclear power plants, atomic bomb, sun/stars
• Other information: Large amounts of energy can be released when the nuclei are combined or split apart.
Nuclear Energy-Type of Potential Energy
Electrical Energy-Type of Potential Energy
• Definition: Electrical energy is energy stored in moving electrons.
• Example 1: Power in power lines and outlets provide electricity to many things in the home.
• Example 2: Lightning is an example of electrical energy in nature.
• Example 3: Static
Thermal Energy-Type of Kinetic Energy
• Definition: Thermal energy is the vibration and movement of the atoms and molecules within a substance.
• Examples: Ice melting, water turning to steam, oven cooking food, etc.
• Other Information:
As an object is heated up, its atoms move faster and spread apart. As an object is cooled, its atoms move slower come closer together.
THINK HEAT (OR LACK OF HEAT)
Radiant Energy-Type of Kinetic Energy
• Definition: Radiant energy is the movement of light or electromagnetic waves.
• Examples: Radiant energy includes sunshine, other visible light forms, x-rays, etc.
Other Information: THINK LIGHT
Travels in waves
Acoustic Energy-Type of Kinetic Energy
• Definition: Acoustic energy is energy produced by an object’s vibrations.
• Examples: stereo playing, birds chirping, clapping, etc.
• Other information
THINK SOUND
Travels in waves
EXAMPLES OF ENERGY:What type(s) of energy are being
shown?1. Roasting marshmallows
EXAMPLES OF ENERGY:What type(s) of energy are being
shown?
1. Roasting marshmallows
Thermal energy because the fire is producing heat.
Radiant energy because the fire is producing light.
Chemical energy because wood is fueling fire.
Acoustic energy because the fire “crackles.”
Mechanical energy because some things are moving and others are not.
EXAMPLES OF ENERGY:What type(s) of energy are being
shown?2. Eating breakfast then going for a
jog
EXAMPLES OF ENERGY:What type(s) of energy are being
shown?Mechanical energy she is in motion.
Chemical energy because the food is giving her energy.
Acoustic energy because she is making noise while chewing and running.
Thermal energy because her body is producing heat.
2. Eating breakfast then going for a jog
EXAMPLES OF ENERGY:What type(s) of energy are being
shown?3. Food being cooked in the microwave
EXAMPLES OF ENERGY:What type(s) of energy are being
shown?Electrical energy because the microwave uses electricity.
Thermal energy because the food is being heated.
Radiant energy because the microwave produces light.
Mechanical energy because some things are in motion and others are still
Acoustic energy because microwave makes sound.
Chemical energy because the food will provide energy for a person.
3. Food being cooked in the microwave
Energy Transformations
Can energy appear or disappear?
No! It just changes forms.
An energy transformation is when energy changes from one form to another.
Law of conservation of Energy
Energy is neither created nor destroyed.
In other words, energy is transformed from one type of energy to another, but the total amount of energy remains the same.
Examples of Energy Transformations
• When you speak into your telephone acoustic energy from your voice is changed into electrical or chemical energy. (A phone plugged into the wall uses electrical energy. A cell phone that is not plugged into the wall runs on chemical energy.) The energy is carried through telephone wires. It is then converted back into acoustic energy on another phone, allowing someone to hear you. The total amount of energy is constant throughout this process.
Examples of Energy Transformations
• To turn on a ceiling fan, you must use mechanical energy to flip on the switch. Then electrical energy is transferred back into mechanical energy and radiant energy (if the fan has a light). Again, the total amount of energy remains the same.
Self Check
Check your understanding by answering the questions from http://www.poweringourfuture.com/students/energy/.