iStarSign inScience 5 · Unit 5: Forces and magnetism · Cambridge Primary Science Stage 5
5.3 Friction, air resistance, water resistance and upthrust
16 questions · e.g. What is friction?
Questions
- a force between two surfaces trying to slide past each other
- the upward push of water
- a magnetic force
- a force that pulls things to Earth
2. In which direction does friction act?
- the same direction as the movement
- always downwards
- always upwards
- opposite to the direction of movement
- a force that slows things moving through air
- the force of gravity
- a force that speeds things up
- the push of water
- a force that slows things moving through water
- a force that speeds up fish
- the force that makes things float
- gravity in water
5. What is another name for air and water resistance?
Check6. Why does a beach ball pushed under water pop back up?
Check7. Why do fish move quickly through water?
- They are heavy.
- They have a streamlined shape, so less drag.
- They have big flat sides facing forwards.
- They have rough skin.
8. A boat floats. Which force pushes it up?
Check9. A boat floats. Which force pulls it down?
Check10. Why do swimmers wear smooth caps?
- to make them sink
- to increase friction
- to make them more streamlined and reduce drag
- to keep their hair dry only
11. How does a parachute work?
- Its big surface catches lots of air, making a lot of air resistance.
- It pushes the person up with upthrust.
- It reduces air resistance.
- It makes the person heavier.
12. Which parachute falls more slowly?
Check13. Which two forces act on a falling parachute?
Check14. Why should you repeat the parachute drop three times?
- to get more reliable results
- because the first drop never counts
- to make it fall faster
- to break the parachute
15. Why do long lorries have a curved shape on top of the cab?
- to increase drag
- to look nice
- to carry more goods
- to reduce air resistance so they go faster and save fuel
16. A log floats in water. Which two forces act on it?
- two forces pulling down
- magnetism and upthrust
- friction and air resistance
- upthrust up and gravity down