Grade 8 · Science · Unit 9 of 13
Systems in Action
Inputs, outputs, safety and automation
What your child practises
Identifying inputs, outputs and purposes of systems including food processing, what makes systems safe and efficient, how automation changes work, and why people's needs and values change systems over time.
Ontario Curriculum expectation: D1.1, D1.2, D2.1–D2.3, D2.8, D2.10 · types of systems, inputs, outputs and components, safe and efficient operation, consumer information, automation and social factors that change systems
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
A thermostat has a sensor. What does the sensor do?
- makes the furnace quieter
- cleans the air
- measures temperature so the furnace can turn on or off
- heats the room directly
Show answer
measures temperature so the furnace can turn on or off
Hint: Sensors give a system information it can respond to.
Question 2
Which is an environmental benefit that automation can sometimes bring?
- no need for materials
- less wasted material because of precise control
- no energy use at all
- more waste in every case
Show answer
less wasted material because of precise control
Hint: Precise machines can cut and fill with less waste.
Question 3
Put the steps of milk processing in order.
- 🥛The milk is packaged in cartons
- 🚜Raw milk is collected from farms
- 🧪The milk is tested for quality
- 🚚Cartons are shipped to stores
Show answer
Raw milk is collected from farms → The milk is tested for quality → The milk is packaged in cartons → Cartons are shipped to stores
Hint: Raw milk is collected, tested, pasteurized, packaged and then shipped.
Question 4
For a washing machine, is each item an input or an output?
Sort into: ⬇️ Input · ⬆️ Output
- 🌡️waste heat
- 🚿fresh water
- 🪣used soapy water
- ✨clean clothes
- 🧴laundry soap
- 👕dirty clothes
- 🔌electrical energy
- 🔊noise
Show answer
⬇️ Input: fresh water, laundry soap, dirty clothes, electrical energy · ⬆️ Output: waste heat, used soapy water, clean clothes, noise
Hint: Inputs go into the system. Outputs come out of it.
Question 5
Why is milk pasteurized?
- It makes milk less white.
- It makes milk freeze.
- It removes all the water.
- Heating kills harmful micro-organisms.
Show answer
Heating kills harmful micro-organisms.
Hint: Pasteurization makes milk safer without changing it much.
Question 6
Why are canned foods heated after being sealed?
- to make the can lighter
- to make labels stick
- to kill micro-organisms so the food does not spoil
- to turn the food into a gas
Show answer
to kill micro-organisms so the food does not spoil
Hint: Heat and a tight seal keep food safe for a long time.