6 th Grade Science Chapter 17 Energy and Resources Notes Section 17.1
What is energy?
Energy is the ability to cause change. Change occurs when energy is transferred from one object to another.
What is kinetic energy?
Kinetic energy is energy an object has due to its motion and mass (KE = ½ mv 2 ).
Key Questions 1
Solar energy, wave energy, sound energy, thermal energy, electrical energy, potential energy and kinetic energy.
Things that move can cause change.
Kinetic energy is the energy an object has due to its motion.
Energy of Motion
If an object isn’t moving, it doesn’t have kinetic energy.
This bullet hits the apple at 1500 ft/second. The bullet gives some of its kinetic energy to the apple.
What causes changes in kinetic energy (KE = ½ mv 2 )?
Kinetic energy increases as an object moves faster. Kinetic energy increases as the mass of the object increases.
What is potential energy?
Potential energy is energy stored in an object because of its position (PE = mgh).
Key Questions 2 The Tadpole Galaxy
If you roll a bowling ball so it moves faster, what happens when it hits the pins?
A faster ball causes more change to occur than a ball that is moving slowly.
Kinetic Energy and Speed
The faster the ball goes, the more kinetic energy it has. This is true for all moving objects.
The Intimidator at Carowinds starts out with a 232-foot (71 m) lift hill that has a 211-foot (64 m) drop angled at 74 degrees. At the bottom of this drop, the train reaches its top speed of 80 miles per hour (129 km/h) and pulls up into the second, 178-foot (54 m) hill.
The seats of the Intimidator set high on the car. There is no belt or over the shoulder harness. Each seat gives a clear view forward and to the sides. This ride really scared Mr. Bradley.
Energy of Position
The potential energy of an object is greater if it is higher above the floor.
Potential energy also depends on mass. The more mass an object has, the more potential energy it has.
Potential energy is the energy associated with an object’s height. When the girl was on the tower she only had a small amount of potential energy. When she jumped off the tower she had a lot more potential energy
A base jumper leaps backwards off the Menara Kuala Lumpur Tower, Malaysia, Wednesday, Oct. 28, 2009. This tower is a 915 feet high communication tower.
What is thermal energy?
Thermal energy is the energy an object has due to its temperature (example - hot chocolate).
What is chemical energy?
Chemical energy is the energy stored in the bonds between atoms (example - candle burning).
Key Questions 3 The Sombrero Galaxy
Chemical energy is the energy stored in chemical bonds.
When chemicals are broken apart and new chemicals are formed, some of this energy is released.
The flame of a candle is the result of chemical energy stored in the wax.
What is light energy?
Light energy is electromagnetic energy that can be absorbed (black shirt in the sun) or reflected (a mirror).
What is electrical energy?
Electrical energy is the energy that is carried by an electric current.
Key Questions 4
Sunlight gives the energy of twelve 100 Watt light bulbs per square yard.
Stone Mountain Laser Show
Nuclear power plants use the energy stored in the nucleus of an atom to generate electricity.
Every atomic nucleus contains energy— nuclear energy —that can be transformed into other forms of energy.
The thousands of mirrors combine to produce temperatures up to 3,000 °C (5,430 °F). 1,420 flat mirrors automatically track the sun and concentrate the light on a parabolic reflector. The reflector then concentrates the rays to produce 1000 kw energy.
When you buy home solar panels for your own use, government programs entitle buyers of solar panels and other similar devices to tax credits and even rebates.
Thunder and Lightning over Beijing
Electrical Power Lines
Explain why a high-speed collision between two cars would cause more damage than a low-speed collision between the same two cars.
Describe the energy transformations that occurs when a piece of wood is burned.
Identify the form of energy that is converted into thermal energy by your body?
Explain how, if two vases are side by side on a shelf, one could have more potential energy.
A golf ball and a bowling ball are moving and both have the same kinetic energy. Which one is moving faster? If they move at the same speed, which one has more kinetic energy?