Warm up #21 Look at the picture. Why does the baby penguin cuddle with its mother?

Lesson 2: Energy Transformations

Essential Questions What is the law of conservation of energy? How does friction affect energy transformations? How are different types of energy used?

Can you transfer energy? activity Hold the handle of the tuning fork and gently strike one arm of it with a mallet. Dip the arms of the tuning fork into a beaker of water. Observe what happens. What happened when the tuning fork was put into the beaker of water? Why do you think that happened? What produced the sound that was hear?

Law of Conservation of Energy What kinds of energy do you see with the flashlight? Where did the missing energy go?

Law of Conservation of Energy What kinds of energy do you see with the flashlight? Chemical energy of battery transformed to electric energy Electric energy transformed into radiant and thermal energy Where did the missing energy go? The environment

Changes Between forms of energy How does energy change forms in the picture?

Is Energy lost when it changes form? activity Energy can have different forms. What happens when energy changes from one form to another? I need 3 students to help me out. Each student gets a bag (1 bag with pennies, 1 bag with beads, 1 bag with paper clips) Each student should exchange 10 items with the student to the right and to the left. Without looking and picking, each student should exchange 10 items with the student to the right and to the left like before. If the pennies, beads, and paper clips represent different forms of energy, what represents changes from one form of energy to another? If each penny, bead, and paper clip represented one unit of energy, did the total amount of energy increase, decrease, or stay the same? Explain.

Changes between kinetic and potential energy The ball slows down as it moves upward and then speeds up as it moves downward; the speed and height change as energy changes from one form to another Why does the ball’s potential energy decrease as the ball falls?

Warm Up #22 What energy transformation takes place when you slam a door?

The law of conservation of energy The total energy in the universe is the sum of all the different forms of energy everywhere Law of conservation of energy – energy can be transformed from one form into another or transferred from one region to another, but energy can’t be created or destroyed

Friction and the law of conservation of energy Friction – a force that resists the sliding of 2 surfaces that are touching There’s always some friction between any 2 substances that are rubbing against each other Rub your hands together What do you feel? What type of energy is this? Where did this energy come from?

Waste energy What is waste energy?

Waste energy What is waste energy? Energy that can’t be used Typically moves into the air Scientists refer to thermal energy that can’t be used as waste energy Some energy is always transformed into useful energy Some energy is always transformed into waste energy

Jump Up and Down You will be working with the person next to you. One person will do jumping jacks while the other one watches After 1 minute, feel your partner’s forehead and your forehead. What do you notice? Is there a difference between the 2 foreheads? If so, how do you explain it?