Energy transfers 2

Starter Problem (in pairs) WIND-UP TOYS Investigate the transfer of Potential energy into to kinetic in………………….. WIND-UP TOYS

WIND-UP TOYS Aim Method: Results: Find out what happens when you increase the number of turns of the toy Method: Wind up your toy once...twice...3 times... When you wind up your toy try to do it always in the same way. Measure how far the toy has moved. Repeat 4 times ..... Why? Results: Fill in the table

Distance travelled (m) Results: Fill in the table below with your results. What relationships do you see? Whay evidence do you have ? Extension Why did you repeat your results? What type of graph might you use to present your reults and why? How reliable where your results and how could you improve this? Number of turns Distance travelled (m)

22/11/2018 How do we describe the transfer of energy from Potential to Kinetic? LO: All Most Some Be able to describe and explain using Sc knowledge and understanding when Potential energy changes to Kinetic energy in a range of systems and what happens the waste energy that is also transferred. Be able to describe how Potential energy is transferred in a range of systems giving examples of where and when it is transferred to Kinetic energy. Describing what happens to ‘Waste energy’ Be able to recognise types of stored Energy and state how Potential energy is stored in a range of systems naming some forms it can be transferred into. Recognising that some energy is ‘wasted’ in the transfer. Keywords: Law of conservation of energy, chemical store, energy store, thermal, kinetic, gravitational potential, elastic, dissipated, Waste

from one form to another Energy changes Energy cannot be made or destroyed, but energy can be changed from one form to another This is called the Conservation of Energy

Conservation of Energy We can have fun changing potential energy to kinetic energy. Top of the hill Going down Walking up 2 High potential energy At the bottom 1 3 Conversion of kinetic energy to potential energy Conversion of potential energy to kinetic energy 4 Low potential energy

Questions Answer in your groups What is the energy stored in the spring of the toy ? Is there a relationship between the number of turns and the distance travelled? How do you store energy inside the toy. What happens to the potential energy when the toy is released?

Conclusions The energy stored in the spring of the toy is called POTENTIAL ENERGY. The more the toy is wound up, the more the energy is stored. The store of energy is done through tightening the spring inside the toy. When the toy is released the potential energy is changed into KINETIC ENERGY.

Potential to kinetic ROLLERCOASTERS

Potential to Kinetic Consider a roller coaster. At the top, it has potential energy. The energy is stored because of its height. It is energy waiting to be used for motion. thecoastercritic.com

Potential to Kinetic As the roller coaster moves toward the bottom, kinetic energy increases along with the rollercoaster’s speed. thecoastercritic.com

Potential to Kinetic Watch this roller coaster. The total energy never changes, it just goes from potential to kinetic and back again.

Investigate in your groups Carry out experiments showing potential energy being changed into kinetic energy.

Investigate energy changes through 3 experiments: Aim Investigate energy changes through 3 experiments: The car and the slope The rubber band The pendulum

A car moving down a slope Find out which kind of energy a car has got: At the top of the slope (C). At the middle of the slope (B). At the bottom of the slope (A). When you push the car back up the slope. A B C

What happens when you let a pendulum go. 2. Rubber band Find out which happens to a rubber band when stretch it and let go. ehow.com Pendulum What happens when you let a pendulum go.

Methods The slope should be 10 cm height. Run your toy car down the slope. Stretch the rubber band. Lift up the pendulum and let it go.

Position of the pendulum Results Decide in your group how to fill the table. Type of energy Position of the car Rubber band Position of the pendulum All potential Some potential and some kinetic All kinetic No kinetic No potential

In a light bulb ? energy changes to Listen and Think Chemical Energy to other energies: ? energy and ? energy The bulb does not make light on its own but it shines when electricity is flowing through it. In a light bulb ? energy changes to ? energy and ? energy.

Chemical Energy to other energies A car needs fuel to make it go. The fuel petrol is a store of chemical energy. This chemical energy is changed into other energies. Fuel rich in chemical energy Heat Waste products poor in chemical Gasoline Oxygen Combustion Kinetic energy of movement Water greenparenthood.com

Waste of energy About 75% of the energy generated by a car’s engine is lost as heat. auto.howstuffworks.com You’d have to run about 14 miles to burn all the calories from a pepperoni pizza. mozzarellispizza.co.uk

Waste of energy We don’t get all of the energy converted into the form we want. Is this a bad thing or a good thing? THINK, PAIR, SHARE