3rd Grade Science--Energy
What is ENERGY?
The ability to do work.--Anything that can do work
EX) Pushing a swing
Does energy have many forms and can it change from one form to another?
EX) Potential energy can change to Kinetic energy
What is Potential Energy?
Stored Energy-- Energy that an object has because of its position & the force that may act on the object.
EX)The higher an object, the more Potential Energy it has if it falls to the ground.
What is Kinetic Energy?
Energy that is the form of energy moving objects have or the energy in motion
What do you use everytime you do work?
Where does most of the energy we use come from?
What is Mechanical Energy?
The TYPE of energy an object has because it can OR is moving.
EX) BICYCLE--If it is moving it has Mechanical Kinetic Energy.
If it is not moving it has Potential Mechanical Energy.
What is Chemical Energy?
A type of energy that come from changes in the very small particles that make up objects.
**ALL matter has these very small particles and thus has potential chemical energy.
What is an example of Potential Chemical Energy?
When you eat your FOOD, your body changes the potential chemical energy into a form that you use to grow and work.
FOOD is the potential chemical energy.
What happens when you USE energy?
It changes from one type of energy to another.
EX) Energy in a flashlight is Stored Potential Energy in the flashlight. When you turn on the switch, it changes to Electircal Light Energy.
What is a conductor?
A material that allows heat energy to move easily through it.
EX) A metal pan is a good conductor of heat. METAL is a good heat conductor.
Name some materials that are NOT good conductors of heat.
Wood, Cloth, Liquids and Gases
How does HEAT ENERGY move?
From a warmer object to a cooler object.
EX) Rubbing hands together creates friction which causes heat.
What is an insulator?
A material through which energy cannot flow easily.
It keeps hot things hot and cold things cold because energy does not move easily through them. EX) A cooler or thermos
Name some examples of good INSULATOR materials.
Wood, Cloth, Liquids and Gases
THere is also a type of insulator in walls and ceilings of homes to help us stay comfortable indoors.
How can heat be produced?
When a chemical change takes a place of matter or by other forms of energy.
What happens when a chemical change occurs?
Heat is often given off.
What is fuel?
A material that is burned to produce useful heat.
EX) Wood, Coal, Gas, and Oil.
What can happen by adding heat?
It can make physical and chemical changes happen faster.
EX) Sugar melts in hot drinks, Hair dryers change electricity into heat/sound, light in electric bulb result in heat.
How can temperature be measured?
With a thermometer.
What is temperature?
A measure of how much heat a place or an object has.
What happens to most things when they get warmer?
They expand or get larger.
What do the lines on the outside of a thermometer stand for?
Units call DEGREES
What are the 2 temperature scales?
Celsius--C--Used the most all over the world
Fahrenheit--F--this is more common in U.S.
What is a thermostat?
Controls the temperature inside a building (like your house or school). If temp. falls below a certain degree, it will turn the heat on.
What is a ray?
A thin line of light.
It can pass throught glass and Water
It CANNOT pass through wood, metal and humans
Can come from many sources
Usually travels in all directions from its source
EX) LIGHT BULB
How does a shadow form?
When light CANNOT pass through a material.
How does light reflect?
When it bounces off an object--We can only see things only when light strikes them.
EX) When you are reading a book.
If an object is not a light source how can we see it?
ONLY when it reflects light to our eyes.
EX) Mirror or a silverware.