T2W1Energy and Energy Transfers

Weekly Plan

Monday/Tuesday

Quiz

Review HW and last week, return tests as needed

Tuesday/ Weigh food for Wednesday Lab

Monday/Tuesday

Energy continues

Wednesday-lab activity—need a volunteer to take 2 pictures of the group and email to me rhonda_george @ssis.asia

Essential Question

Why can energy not be created or destroyed?

Learning Objectives

Relate energy requirements to food intake

Consider the energy conversions taking place in a power station.

Provide examples of fuels Choose appropriate energy sources for future use

Vocabulary

Conduction

Convection

Radiation

Insulator

Kinetic energy

Potential energy

Thermal energy

Heat vs. temperature = joules vs. oC

Monday Quiz

1. An object at rest on top of a shelf is likely to have:

A. no energy

B. gravitational

C. potential energy

2. Batteries are stores of:

A. chemical energy

B. energy

C. light energy

3. Energy is usefully transferred from a personal audio player as:

A. kinetic energy

B. thermal energy

C. sound energy

4. Which is likely to contain the most thermal energy?

A. a red hot horseshoe

B. a spark from a firework

C. an ice cube

5. Which is likely to have the highest temperature?

A. a red hot horseshoe

B. a spark from a firework

C. an ice cube

6. Which ways to transfer thermal energy rely on moving particles of solids, liquids and gases?

A. conduction and radiation

B. convection and radiation

C. conduction and convection

7. Thermal energy is transferred by conduction from:

A. the hot end to the cold end

B. the cold end to the hot end

C. the Sun to the Earth

8. Which of the following is a non-renewable energy resource?

A. wind power

B. biomass

C. natural gas

9. Where did the energy stored in fossil fuels originally come from?

A. plants

B. sunlight

C. animals

10. What is an advantage of wind power?

A. it doesn't work unless there is wind

B. it uses large wind turbines

C. it is a renewable energy resource

11. Which of the following is a good way to reduce the use of fossil fuels?

A. walking instead of going in a car

B. leaving the TV on standby all night

C. leaving the lights on when we leave a room

12. All objects radiate heat energy. Heat radiation does/does not require particles to transfer itself. It can be transferred through a vacuum.

13. Draw a energy transfer diagram from one of your three for your homework assignment. Remember:

type of energy conductor or transformer type of energy

14. Energy cannot be ____________ or ____________only stored or _____________.

Vocabulary

Conduction

Convection

Radiation

Insulator

Define the 4 vocabulary words in your jotter book.

CCR

Check out this demonstration of conduction, convection and radiation

http://www.wisc-online.com/objects/heattransfer/

Conduction

Conduction

When a substance is heated, its particles gain energy and vibrate more vigorously. The particles bump into nearby particles and make them vibrate more. This passes the thermal energy through the substance by conduction, from the hot end to the cold end.

Convection

Convection

Heat is transferred from one place to another is convection. Convection takes place when heated molecules move from one place to another, taking the heat with them. Convection is common in both the atmosphere as well as in the oceans.

Convection

Convection also takes place within the Sun. Vast amounts of hot gas rise up towards the surface of the Sun. As they do so, they become cooler and begin to fall back down towards the center of the Sun. As they do so, they again heat up and begin rising again, over and over, rising and falling in a seemingly eternal circular pattern.

Convection

Convection

The particles in liquids and gases can move from place to place. Convection happens when particles with a lot of thermal energy in a liquid or gas move, and take the place of particles with less thermal energy. Thermal energy is transferred from hot places to cold places by convection.

Radiation

Radiation

All objects radiate energy and heat, even your own body. However, the radiation coming from hotter objects is more intense than that coming from cooler objects. Radiation leaves an object in the form of waves. The hotter an object, the shorter the wavelength of this radiation.

RadiationRadiation

All objects transfer thermal energy by infrared radiation. The hotter an object is, the more infrared radiation it gives off.

No particles are involved in radiation, unlike conduction and convection. This means that thermal energy transfer by radiation can even work in space, but conduction and convection cannot.

Radiation is how we can feel the heat of the Sun, even though it is millions of kilometres away in space.

Infrared cameras give images even in the dark, because they are detecting heat, not visible light.

Review Energy

Let’s review energy transfer and storage, using the website below on bitesize.

Please review the information at the website below. At the end, you will need to do a sketch of the electrical power station.The drawing will be counted as homework!! Due Wednesday!

http://www.bbc.co.uk/bitesize/ks3/science/energy_electricity_forces/energy_transfer_storage/revision/1/

Name of food

Temperature of water at the start

Temperature of water at the end

Rise in temperature

This week’s investigation

We need to do some preparation work for this weeks investigation.

How will you heat/burn the food—give this information.

We will be investigating food energy so we need to measure equal masses of two types of food—bread(toast) and crackers

Each group of 2 people needs to get 5 crackers and weigh them

After you weigh the crackers, measure out that amount of toast(dried bread) so you have equal masses

Record this information (mass of both foods in grams) in your jotter book—use the following table template