Power+and+energy

9I Buying energy

Power and energy
Recall the units for measuring power. Explain how to find the power of an appliance. Recall which kinds of appliances transfer the most energy. Explain why it is better to use more efficient appliances.
 * Outcomes (what you will be able to do by the end of this lesson) **


 * Starter**
 * Review homework and completed work from last lesson
 * Key term quiz

> Extension: some items do not have a wattage written on them. For these you will need to calculate the watts. Remember the equation from the extension last lesson? Power (W) = Voltage (V) x Current (A)
 * Activities**
 * 1) Complete Qs 1-4 from p112-113 of Exploring Science 9.
 * 2) Create a two column table (//appliance, watts used (W)//). Circulate around the room and identify the power rating of all the appliances, write down your findings in the table.
 * 1) Where is the energy used in a typical home? Complete [[file:ES9_Id112_09msu.xls|Energy use]] to find out. In your groups discuss sensible estimates for how often the different appliances are used. Print-off and paste into your book the completed table and chart (ask if you need help to figure out how to put both on a single page).
 * 2) Complete [[file:ES9_CHAP_Id4.pdf|Efficient lighting]] to assess the cost and energy efficiency of the different types of light bulb.
 * 3) Complete [[file:ES9_CHAP_Id6.pdf|Paying for electricity]] to find out how to calculate energy costs.


 * Summary**
 * Review completed classwork / key term quiz
 * Discuss how energy is wasted (both at school and home), reasons why it is wasted and what we can do to save more energy

Download complete the gapfill on, print-off and stick into your exercise book. You can copy and complete if you have a problem printing.
 * Homework**** activity options **


 * Useful links**