New
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Comparing the speeds of different parachutes
I can explain how the size of a parachute affects its top speed.
Lesson 9 of 10
New
New
- Year 8
Comparing the speeds of different parachutes
I can explain how the size of a parachute affects its top speed.
Lesson details
Key learning points
- The larger the surface of a parachute, the bigger its drag.
- Gravity pulls down with a steady force.
- At top speed the force of drag on a parachute is the same size as the force of gravity on the jumper.
Keywords
Drag - When an object moves through a fluid there is a drag force that opposes the movement.
Parachute - A parachute is used to increase the size of drag forces. This slows down the object it is attached to.
Gravitational force - The gravitational force on something pulls it downwards, towards Earth.
Resultant force - A resultant force is the overall effect of a set of forces on an object, taking their directions into account.
Common misconception
Students may think that all objects fall at the same rate (this is only true in a vacuum).
Use force diagrams to discuss the effect of different sized drag on the parachutes, linking this to resultant force and acceleration.
The investigation can be extended by using squared paper. This allows the area of the parachute to be determined and the students can find a quantitative relationship between the fall speed and the area using a graph.
Teacher tip
Content guidance
- Risk assessment required - equipment
Supervision
Adult supervision required
Licence
This content is © Oak National Academy Limited (2026), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Which force causes objects to fall to the ground?
Which force causes objects to fall to the ground?
friction
electromagnetic
tension
Q2.Why is a force represented by an arrow on a diagram? Choose the best answer.
Why is a force represented by an arrow on a diagram? Choose the best answer.
Forces have magnitude (size).
Forces have direction.
The colour of the arrow indicates the type of force.
Q3.Which force opposes movement through liquids?
Which force opposes movement through liquids?
gravitational
tension
magnetic
reaction
Q4.At the end of a race a car opens a parachute. Why do they do this?
At the end of a race a car opens a parachute. Why do they do this?
The drag force decreases and this slows the car down.
The driving force increases and this slows the car down.
The driving force decreases and this slows the car down.
Q5.A car moving along a flat road has an unbalanced forwards force acting on it for 30 s. What will happen to the car's movement?
A car moving along a flat road has an unbalanced forwards force acting on it for 30 s. What will happen to the car's movement?
The car will stay at the same speed for the 30 s.
The car will quickly speed up and then move at a steady speed for 30 s.
The car will slow down.
The car will speed up and slow down throughout the 30 s.
Q6.An emergency food parcel is dropped from a plane. Near the ground the parachute opens. What happens to the movement of the food parcel?
An emergency food parcel is dropped from a plane. Near the ground the parachute opens. What happens to the movement of the food parcel?
It starts moving upwards.
It immediately changes to a new constant speed.
It stops moving immediately.
There is no change in the movement.
Assessment exit quiz
6 Questions
Q1.Match the key words to their explanations.
Match the key words to their explanations.
Q2.When does a falling object reach a steady top speed?
When does a falling object reach a steady top speed?
When there is no drag force.
When the gravitational force is less than the drag force.
When the gravitational force is greater than the drag force.
Q3.During a test. a pupil drops paper parachutes with different surface areas but equal weights. Which is the correct prediction about the fall speed?
During a test. a pupil drops paper parachutes with different surface areas but equal weights. Which is the correct prediction about the fall speed?
The parachutes will all have the same fall speed.
The parachute with the greatest surface area will have the greatest fall speed.
The parachute with the middle surface area will have the greatest fall speed.
Q4.In a parachute drop test the times recorded are 1.21 s, 1.24 s, 1.23 s and 1.28 s. What is the mean time?
In a parachute drop test the times recorded are 1.21 s, 1.24 s, 1.23 s and 1.28 s. What is the mean time?
1.21
1.23
1.28
4.04
Q5.A skydiver is falling with their parachute closed. What happens to the size of the forces on them immediately after opening the parachute?
A skydiver is falling with their parachute closed. What happens to the size of the forces on them immediately after opening the parachute?
The gravitational force increases and the drag force increases.
The gravitational force increases and the drag force decreases.
The gravitational force stays the same and the drag force decreases.
The gravitational force stays the same and the drag force stays the same.
Q6.A parachute is tested five times, falling through 1.5 m. The times are: 0.80 s, 0.70 s, 0.72 s, 0.77 s and 0.76 s. Calculate the average fall speed.
A parachute is tested five times, falling through 1.5 m. The times are: 0.80 s, 0.70 s, 0.72 s, 0.77 s and 0.76 s. Calculate the average fall speed.
1.0 m/s
1.2 m/s
1.5 m/s
11.3 m/s
