Year 9 Science · Unit 3 · Lesson 6
Foundation Worksheet
Learning Goals
Match each term to its definition
Draw a line connecting each term on the left to its correct definition on the right. Or write the matching letter next to each term.
| Term | Your answer | Definition |
|---|---|---|
| Work | A. The rate at which energy is transferred; equal to work done divided by time | |
| Power | B. The SI unit of energy and work; equal to one newton-metre | |
| Watt | C. The fraction of input energy that is converted into useful output energy, expressed as a percentage | |
| Joule | D. The SI unit of power; equal to one joule per second | |
| Efficiency | E. The energy transferred when a force moves an object in the direction of that force; W = F × d | |
| Force × distance | F. The formula used to calculate work done, where force is in newtons and distance is in metres |
True or False? Fix the false ones
Circle T or F for each statement. If the statement is false, rewrite it correctly on the line below.
Carrying a heavy box upstairs without moving it sideways requires no force, so no work is done.
Correct it:
A 100 W light globe uses 100 joules of electrical energy every second.
Correct it:
A more powerful machine always does more total work than a less powerful one.
Correct it:
Efficiency can never be greater than 100% because you cannot get more useful energy out than the total energy you put in.
Correct it:
Pushing against a brick wall with all your strength does scientific work on the wall, because you are exerting a large force.
Correct it:
1. A student pushes a 20 N trolley 15 m across a supermarket car park. Calculate the work done. Show your working and include the correct unit.
2. In science, holding a heavy box still at arm's length does zero work on the box. But your muscles are clearly doing something, where does the energy your body uses actually go?
Wrap Up
In one sentence, what was the main idea of this lesson?