Bellringer What biome has few trees and lots of grasses with a long dry season and a short wet season? What do we call the variable that we measure in an experiment? What phase of the moon does a lunar eclipse occur? What type of tide occurs during 1st and 3rd quarter moons?

Bellringer What biome has trees with leaves that have a waxy coating and cool temperatures? What organisms get their energy from the sun? What phase of the moon comes after waxing crescent? What eclipse occurs during a new moon? What is the original source of wind?

What are Kinetic and Potential Energy?

What is Energy? Energy is the ability to do work. Work is done when a force causes an object to move in the direction of the force. Everything that happens in the world uses energy! Most of the time we can’t see energy, but it is everywhere around us!

Energy… Law of Conservation of Energy-energy can NEVER be created or destroyed! It can only be STORED or TRANSFERED.-

How is all energy divided? Potential Energy Kinetic Energy

Kinetic Energy In tennis, energy is transferred from the racket to the ball. As it flies over the net, the ball has kinetic energy. Kinetic energy is the energy of motion. All moving objects have kinetic energy. Like all forms of energy, kinetic energy can be used to do work. For example, kinetic energy allows a hammer to do work on a nail.

Examples of Kinetic Energy:

Kinetic Energy Two things can affect the amount of kinetic energy of something. Its mass…. Simply put, the bigger something is, the greater its energy. Its velocity(speed)…. Again, pretty simple. The faster it moves, the more energy it has. KE = M x V (This might remind you of the formula for force…. How do force and energy relate to each other?)

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!

Potential Energy Is the energy an object has because of its position. Example: The bow has energy because work has been done to change its shape.

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

Example of Potential Energy

The ball at the top of the hill has a great deal of potential energy.

Kinetic vs. Potential Energy At the point of maximum potential energy, the car has minimum kinetic energy.

Kinetic-Potential Energy Conversions As a basketball player throws the ball into the air, various energy conversions take place.

Ball speeds up Ball slows down

Elastic Potential Energy Energy can be stored in bowstrings, springs, and rubber bands. You change the shape of these objects by stretching them.

Gravitational Potential Energy When an object is lifted off the Earth’s surface. You use a force that is against the force of gravity. Books on a shelf have gravitational potential energy.

Chemical Potential Energy Potential energy stored in chemical bonds. Before you eat that sugary drink or food, it has the potential to give you energy. Food and drinks have chemical potential energy due to their chemical composition.

Chemical Potential Energy Batteries, gasoline, matches, and fireworks also have chemical potential energy.

Practicing with whiteboards

Potential or Kinetic? An apple on a tree.

Potential or Kinetic? A rolling ball.

A stretched rubber band. Potential or Kinetic? A stretched rubber band.

Gravitational, Elastic, or Chemical? Our food and drink.

Gravitational, Elastic, or Chemical? A book on a shelf.

Gravitational, Elastic, or Chemical? A stretched rubber band.

Which object has 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

Which one has more Kinetic energy? If Ms. Russell rolled a bowling ball and a soccer ball down the aisle at the same speed, which one would have more kinetic energy?

Which one has more Kinetic Energy? A red tennis ball rolling slow or a blue tennis ball rolling fast?