Review: forces, people and community
Pushes and pulls are forces. A force can start a motion, stop it or change its direction, and a bigger force makes a bigger change. A pendulum with a shorter string swings more times in 15 seconds. A magnet attracts things made of iron or steel, but not wood, plastic or paper, and not every metal. Like poles repel and unlike poles attract. Magnets work from a distance and through thin paper, but they pull less as the distance grows. A compass needle is a small magnet that points north. Engineers follow the steps ask, imagine, plan, build, test and improve, and a cost sheet multiplies the number of items by the cost of each. People in a community connect in many ways. Technology means tools and machines that solve problems. Transport moves people and goods, and regions trade goods and labour. A computer has input, a processor, memory, storage and output. We keep a balance with screen time, and we keep private information private. A newspaper has a headline, a byline, articles and captions. A good interview uses open questions. A public service message is clear, supported by facts and caring. A cartoon tells a story in panels. For a mural, the perimeter is the distance around it and the area is the space it covers.
| Test | Result |
|---|---|
| steel nail and a magnet | attracted |
| wooden pencil and a magnet | not attracted |
| north pole near north pole | push apart |
| north pole near south pole | pull together |
| Item | Number | Cost of each (LE) | Total (LE) |
|---|---|---|---|
| stick | 5 | 2 | 10 |
| magnet | 3 | 4 | 12 |
| Total cost | 22 |
Review challenge. 1) Test five objects with a large school magnet, with a grown-up, and write the rule. 2) Predict what happens to the number of swings if a pendulum string is made shorter, then check with your results from earlier. 3) Make a safety poster for the class newspaper: “Keep magnets away from phones and cards, and never near your mouth.” Check that it is clear, has a fact and is caring. 4) Plan a mural panel with a word, a symbol and a message about helping each other. 5) Choose one of the six design steps and explain it to a friend.