Resources: A feather, a tennis balls, small plastic toys/weights, stopwatches, a variety of materials to test (e.g. different types of papers, plastic bags and bin bags), rulers, a hole punch, string and calculators.
Core Handout (2): Investigation sheet for children to record their predictions, fair testing, results and conclusions.
Stretch Handout (3): Children are asked to draw a diagram of a parachute's descent with labelled arrows showing the forces acting on the parachute. They are then asked to explain the purpose of a parachute.
Enquiry Approach - Problem-solving
Applying prior scientific knowledge to solve problems and answer further questions.
Enquiry Skill - Setting up tests
Carefully following a method and using equipment accurately to carry out a scientific enquiry. The method may be designed by teachers or children themselves.
Ask the children to answer the question: If a ball and a hammer were dropped from the same height, which would reach the ground first? Address any misconceptions the children have and remind them that the mass of an object does not affect the pull of gravity, so the objects will fall at the same rate. Recall that mass is measured in grams/kilograms (g/kg) and weight is measured in Newtons (N).
Explore the life and work of Galileo and discover his influential experiment on gravity. Drop a feather and tennis ball from the same height and observe what happens. Knowing that the mass of an object does not influence how quickly it falls to the ground, discuss some possible reasons for the differences the children see.
Explain that air resistance is a force which acts as friction between the object and air. It is sometimes known as drag and is an opposing force to gravity. Explore some everyday examples of when the children may observe air resistance. Observe how aeroplanes and bullet trains are streamlined so that they create as little resistance as possible. Explore how parachutes are used to slow down the discovery spacecraft and a sky diver’s descent.
Career Film: Take a tour around Rolls Royce SMR's Heritage Museum in Derby to find out about Chloe Magee's job. Chloe works as an Indirect Buyer for Rolls Royce SMR.
Expert Film: This is Osman Bawa. Osman works as the Integrated Management Systems Manager for Rolls Royce SMR. Listen to Osman as he describes air resistance.
Ask the children to design an investigation to test how to create the best parachute. They will decide which variable they will test and, therefore, which they will control. In small groups, the children could test variables such as size and material.
The control variables are the height from which the parachute is dropped (ideally, this should be high, so, under supervision, a climbing frame or gym apparatus could be used), the weight of the object falling, the length of string and the size of the parachute/the material used to create the parachute (respective to which they are investigating).
Ask the children to follow the prompts on the handout to firstly make a prediction and then record the results from the investigation. The children should conduct 3 tests and then find an average to get a more accurate set of results. Ask them to write a conclusion to the investigation question.
Challenge Task: Ask the children to draw a diagram of one parachute’s descent, with labelled arrows showing the forces acting on the parachute. Explain the purpose of a parachute.
Discuss the findings from the children’s experiment. Show a video of the Apollo 15 hammer and feather drop experiment on the moon (1971). Observe that the hammer and feather fall at the same rate. Pause the video to discuss possible reasons for this. This is due to the fact that the moon has no atmosphere, so there is no air resistance.
Air resistance, also known as drag, is a force that opposes the motion of an object as it moves through a fluid, such as air. When an object moves through the air, it experiences air resistance, which depends on several factors, including the object's shape, size, and speed.
Parachutes work by taking advantage of air resistance. A parachute is a device that is used to slow the descent of an object, typically a person or cargo, as it falls through the air. When a person jumps out of a plane with a parachute, the air resistance acting on the large surface area of the parachute slows the person's descent and reduces the force of impact when they land on the ground.
The shape and size of a parachute are designed to increase air resistance and slow down the fall of an object. The parachute is typically made of a large canopy that is attached to the person or cargo by suspension lines. When the parachute is opened, the canopy fills with air, increasing its surface area and creating a large amount of air resistance. This air resistance opposes the force of gravity, slowing down the fall of the object and reducing the impact of landing.
The amount of air resistance acting on a parachute depends on several factors, including the size of the canopy, the shape of the parachute, the weight of the person or cargo, and the speed at which they are falling. Parachute designers must take all of these factors into account when designing parachutes for different purposes, such as military parachutes, sport parachutes, and emergency parachutes.
In conclusion, the connection between air resistance and parachutes is that the large surface area of the parachute creates a significant amount of air resistance, which slows down the fall of an object and reduces the force of impact when it lands on the ground. By taking advantage of air resistance, parachutes allow people and cargo to safely descend from great heights.