Streamlining | Science | Quizalize & Oak National Academy

Starter quiz

Which of these is used to mean the overall effect of a combination of forces, taking their direction into account?
- the ultimate force
- the final force
- the total force
- the resultant force ✓
- the force sum
Air resistance is an example of what kind of force?
- tension
- gravitational
- upthrust
- drag ✓
- non-contact
When a resultant force acts on an object it can speed up or slow down. What word is used to describe an increase in speed?
- 'acceleration' ✓
The figure shows the forces on a van. What is happening to the van?
- It must be stationary.
- It is speeding up. ✓
- It is slowing down.
- It is moving backwards.
- It is moving at a constant speed.
A person pulls on a stationary box. It starts moving towards them. Which statement is correct.
- The size of the pull must be greater than the weight of the box.
- The size of the pull must be less than the weight of the box.
- The size of the pull is greater than the friction between the box and the floor. ✓
- The size of the pull is less than the friction between the box and the floor.
Which of these are parts of Newton's first law of motion? When there is no resultant force ...
- a stationary object will start to move.
- a stationary object will stay stationary. ✓
- a moving object will slow down.
- a moving object will change direction.
- a moving object keeps moving at the same speed in the same direction. ✓

Exit quiz

Match the key words with the explanations.
- Drag
  
  ⇔
  
  The force that acts when an object moves through a fluid. ✓
- Air resistance
  
  ⇔
  
  The drag force in air. ✓
- Water resistance
  
  ⇔
  
  The drag force in water. ✓
- Streamlined
  
  ⇔
  
  Shaped so that it moves through liquids/gases more easily. ✓
A car is travelling at high speed and opens a parachute. Which force increases when the parachute is opened?
- 'drag' ✓
Which features of a rocket-propelled car will allow it to reach a very high speed?
- it creates high air resistance
- it is streamlined ✓
- it produces a large drag force
- it produces a large thrust force ✓
A sky diver jumps out of an aeroplane and speeds up until they reach a top speed. Which statements are true?
- The weight of the skydiver has reached zero.
- The drag of the skydiver has reached zero.
- There is no vertical resultant force. ✓
- The weight of the skydiver is equal in size to drag force. ✓
- There are no vertical forces acting on the skydiver.
Four identical marbles are dropped from the same height into containers of different fluids. Starting with the shortest time, put them into order of how long it takes them to reach the bottom.
- 1
  
  ⇔
  
  Marble falling through air.
- 2
  
  ⇔
  
  Marble falling through water.
- 3
  
  ⇔
  
  Marble falling through cooking oil.
- 4
  
  ⇔
  
  Marble falling through honey.
Which of these statements explains why streamlining can increase the maximum speed of a lorry.
- Streamlining will reduce the mass of the lorry.
- Streamlining increases the maximum driving force of the lorry.
- A streamlined lorry will push fewer air particles out of the way per second. ✓
- A streamlined lorry will fit between air particles and avoid hitting them.
- The drag force on the lorry will be less when it is streamlined. ✓

Worksheet

Loading worksheet ...

Presentation

Loading presentation ...

Video

Lesson Details

Key learning points

Streamlining reduces drag.
Streamlining reduces how much a fluid needs to be pushed out of the way for an object to move through it.
The drag force on an object moving through a fluid (liquid or gas) increases with speed.
Streamlining can increase the top speed of a vehicle.

Common misconception

Pupils often do not recognise the existence of a drag force on an object moving through air.

Demonstrate the effect of drag forces by dropping pieces or paper (folded and unfolded) and show they reach the ground at different times.

Keywords

Drag - When an object moves through a liquid or a gas (a fluid), a drag force acts on it as it pushes particles out of its way.
Air resistance - The drag force on an object moving through air is called air resistance.
Streamlined - A streamlined object is shaped to reduce the drag forces acting on it.
Water resistance - The drag force on an object moving through water is called water resistance.