Describe the differences between kinetic and potential energy. Define energy. Describe the differences between kinetic and potential energy. On the roller coaster below, at what points would kinetic energy be increasing? On the roller coaster below, at what points would potential energy be increasing? G AA AB F D AC E H

Energy

What is ENERGY? Energy is the ability to do work. Everything that happens in the world uses energy! Most of the time we can’t see energy, but it is everywhere around us!

Remember: ALL matter is made up of atoms. Atoms NEVER stop moving. Therefore all matter has energy

Energy… is NEVER created or destroyed! can only be STORED or TRANFERRED. This is called the Law of Conservation of Energy

How is all energy divided? Potential Energy Kinetic Energy

Potential Energy is… The energy stored in an object. "Potential" simply means the energy has the ability to do something useful later on.

Examples of Potential Energy: A stretched rubber band.. Water at the top of a waterfall.. Yo–Yo held in your hand.. A drawn Bow and Arrow…

Two types of Potential Energy Gravitational potential energy: Comes into play when an object is off the ground. The object “could” fall and so it would have potential energy. The higher the object is off the ground the more energy it has. Elastic potential energy: When you stretch a rubber band, you are creating potential energy. The object “could” move forward and so it has potential energy. The more we pull the rubber band back, the more energy it has.

Gravitational Potential Energy Formula: PE = mgh Potential Energy = mass x gravity x height Mass must be in kilograms. Gravity is constant at 9.8m/s2 Height must be in meters.

The higher an object, the more potential energy. The more mass an object has, the more potential energy it has.

Which object has more potential energy?

ANSWER A This brick has more mass than the feather; therefore more potential energy!

Changing an objects’ height can change its potential energy. If I want to drop an apple from the top of one of these three things, where will be the most potential energy? A C B

ANSWER A The higher the object, the more potential energy!

Gravitational Potential Energy Formula: PE = mgh= Joules Potential Energy = mass x gravity x height Mass must be in kilograms. Gravity is constant at 9.8m/s2 Height must be in meters.

Honors

Calculating PE = mgh A bowling ball is sitting at the top of a hill that is 20 m high. The bowling ball has a mass of 1.2 kg. PE= 235.2 Joules

Calculating PE = mgh There is a bell at the top of a tower that is 45 m high. The bell weighs 15 kg. PE = 6615 Joules

Calculating PE = mgh A cinder block is sitting on a platform 24.2 m high. It weighs 8 kg PE= 1897.28

Kinetic Energy

Potential Energy Converted to Kinetic Energy… When stored energy begins to move, the object now transfers from potential energy into kinetic energy.

Kinetic Energy Is… The energy of a moving object. "Kinetic" means movement! When stored energy is being used up, it is making things move or happen.

Examples of Kinetic Energy:

The faster the object moves, the more kinetic energy is produced. The greater the mass and speed of an object, the more kinetic energy there will be.

When these objects move at the same speed, which will have more kinetic energy?

ANSWER The semi- truck has more mass; therefore, more kinetic energy!

An object has the MOST kinetic energy when it’s movement is the GREATEST. When an object has the LEAST potential energy, it has the MOST kinetic energy.

Kinetic and Potential Energy Kinetic and potential energy generally work in a seesaw motion. As one increases generally the other decreases. Kinetic Potential Potential Kinetic Kinetic and Potential Energy

https://www.youtube.com/watch?v=Jnj8mc04r9E https://oeta.pbslearningmedia.org/resource/hew06.sci.phys.maf.rollercoaster/energy-in-a-roller-coaster-ride/#.WczixdtSzow

A water bottle is knocked off a desk A water bottle is knocked off a desk. When does the bottle have the MOST kinetic energy? A. At the top of the fall. B. In the middle of the fall. C. At the bottom of the fall.

C. At the bottom of the fall. It has the most kinetic energy when its movement and speed are greatest, which is at the bottom of the fall right before it hits the ground. When an object has the LEAST potential energy is when it has the MOST kinetic energy. BrainPop

Roller Coasters When does the train on this roller coaster have the MOST potential energy? AT THE VERY TOP! The HIGHER the train is lifted by the motor, the MORE potential energy is produced. At the top of the hill the train has a huge amount of potential energy, but it has very little kinetic energy.

As the train accelerates down the hill the potential energy is converted into kinetic energy. There is very little potential energy at the bottom of the hill, but there is a great amount of kinetic energy.

When does the train on this roller coaster have the MOST kinetic energy? (When is it moving the fastest?) (When does it have the LEAST potential energy???) At the bottom of the tallest hill!

Kinetic Energy Formula: KE = ½ mv2 = Joules ½ mass x velocity2 Mass in kilograms Velocity in meters per second squared

Honors

Calculating Kinetic Energy KE = ½ mv2 A 26 kg object is moving at a velocity of 10 m/s. KE= 1,300 Joules

Calculating Kinetic Energy KE = ½ mv2 You serve a volleyball with a mass of 1.8 kg. The ball leaves your hand with a speed of 40 m/s. KE = 1440 Joules

Calculating Kinetic Energy KE = ½ mv2 A car is traveling with a velocity of 30 m/s and has a mass of 1220 kg. KE = 137,250 Joules

Design an Experiment Does more potential energy create more kinetic energy? How could we prove it and provide evidence? Gravitational Elastic

Energy

Does more PE= more KE? Gravitational Potential Energy: Tennis Ball Elastic Potential Energy: Rubber Band

Gravitational Energy How high should we drop the ball from? How will we measure kinetic energy? How can we reduce error? What will our data collection look like?

Elastic Potential Energy How far should we draw the rubber band back? How will we measure kinetic energy? How can we reduce error? What will our data collection look like?

Elastic Potential Energy Draw Distance Trial 1 Trial 2 Trial 3 Average 20 cm 25 cm 30 cm 35 cm 40 cm

Gravitational Potential Energy Drop Height Trial 1 Trial 2 Trial 3 Average 1 m 2 m 3 m 4 m 5 m

Data Collection

Graphing

Reflection Does more potential energy mean there is more kinetic energy? Explain using the data you gathered. What are some other ways in which we could have tested the same concept? What were some potential errors that could have occurred during data gathering? Give multiple reasons. What would you change in the experiment if you were asked to do it again? Must give at least 3 things you would change and why.

https://oeta. pbslearningmedia. org/resource/hew06. sci. phys. maf https://oeta.pbslearningmedia.org/resource/hew06.sci.phys.maf.trebuchet/energy-transfer-in-a-trebuchet/#.WdTPRttSzow

Which has a bigger effect? Which as a bigger effect on the amount of kinetic energy? Mass or Velocity? Prove it.

Notes All energy is divided into two types: potential and kinetic. Potential Energy: The energy stored in an object. Kinetic Energy: The energy of a moving object. Energy is never created or destroyed. It is always stored or transferred.