Lift is the upward force on man-made flying objects and living things that allows them to become and remain airborne. It is the force that counteracts weight and gravity. How is lift achieved? Is lift the only upward force that could affect flying objects?
Students should be given opportunities to discover how flying objects interact with the air around them to achieve lift. Some things, like hot air balloons, achieve an upward motion through buoyancy. Others, like planes, birds, and insects achieve lift by the shape of their wings. How does it all work? Let's explore and find out!
Background knowledge you should know:
Bernoulli's principle: Because wings are curved, the air that passes over the top of the wing moves faster than the air under the wing. Faster moving air has less pressure than slower moving air, meaning there is more pressure on the bottom of the wing than the top. The higher-pressure air pushes upward on the bottom of the wing, causing it to lift.
Buoyancy: When an object enters a fluid (like water or air), it takes up the space of that fluid, displacing (pushing) it elsewhere. The fluid exerts the same force on the object that it did on itself before it was displaced. This force is called buoyancy. If the force of buoyancy is stronger than the force of gravity, the object will rise, like floating! For example, when you enter the water at a pool, you displace the water, meaning you push the water aside to make room for your body. The water exerts the same upward force on you that it did on the water you displaced, which is why you feel pushed up. Some flying objects, like hot air balloons, work the same way! When the air is heated, the air particles inside the balloon start colliding faster and the air expands, taking up more room. It displaces the air that was there before. Since the balloon is lighter than the air it displaced, the pressure of the air causes it to rise.
Here are some resources you and the student can explore to investigate how lift affects flying objects. They fit into the Nova Scotia Grade 6 Science Curriculum by exploring the outcome: Learners will evaluate factors that influence flight.
*Please note that lift can be difficult for some students to grasp as it is very informational and includes new scientific principles they are not familiar with. I would recommend spending a bit more time on it if possible. It would be beneficial to spend a couple of days on it to not overload the students.
1) Activity: Make a hot air balloon - An activity created by me to explore the concept of buoyancy.
Students should be given opportunities to discover how flying objects interact with the air around them to achieve lift. Some things, like hot air balloons, achieve an upward motion through buoyancy. Others, like planes, birds, and insects achieve lift by the shape of their wings. How does it all work? Let's explore and find out!
Background knowledge you should know:
Bernoulli's principle: Because wings are curved, the air that passes over the top of the wing moves faster than the air under the wing. Faster moving air has less pressure than slower moving air, meaning there is more pressure on the bottom of the wing than the top. The higher-pressure air pushes upward on the bottom of the wing, causing it to lift.
Buoyancy: When an object enters a fluid (like water or air), it takes up the space of that fluid, displacing (pushing) it elsewhere. The fluid exerts the same force on the object that it did on itself before it was displaced. This force is called buoyancy. If the force of buoyancy is stronger than the force of gravity, the object will rise, like floating! For example, when you enter the water at a pool, you displace the water, meaning you push the water aside to make room for your body. The water exerts the same upward force on you that it did on the water you displaced, which is why you feel pushed up. Some flying objects, like hot air balloons, work the same way! When the air is heated, the air particles inside the balloon start colliding faster and the air expands, taking up more room. It displaces the air that was there before. Since the balloon is lighter than the air it displaced, the pressure of the air causes it to rise.
Here are some resources you and the student can explore to investigate how lift affects flying objects. They fit into the Nova Scotia Grade 6 Science Curriculum by exploring the outcome: Learners will evaluate factors that influence flight.
*Please note that lift can be difficult for some students to grasp as it is very informational and includes new scientific principles they are not familiar with. I would recommend spending a bit more time on it if possible. It would be beneficial to spend a couple of days on it to not overload the students.
1) Activity: Make a hot air balloon - An activity created by me to explore the concept of buoyancy.
activity_-_hot_air_balloons.docx | |
File Size: | 15 kb |
File Type: | docx |
2) Activity: Bernoulli's Principle - An activity created by me to explore the concept of lift through wing shape and Bernoulli's Principle.
activity_-_bernoulli.docx | |
File Size: | 15 kb |
File Type: | docx |
3) Video: Bill Nye the Science Guy - Flight. A great video that describes and demonstrates lift and Bernoulli's principle in student-friendly language.
4) Bill Nye - Flight video companion sheet. Fill out the sheet as your watching the video!
bill-nye-flight.docx | |
File Size: | 21 kb |
File Type: | docx |
5) Video: How do Airplanes Fly? This video demonstrates how air moves around the wings to create lift.
6)Website: Factors Affecting Lift. This interactive website explores why wings have the shape they do.
https://howthingsfly.si.edu/aerodynamics/factors-affecting-lift
7) Video: Loose in the Lab with Bernoulli's Tent. A video demonstration of Bernoulli's principle.
8) Video: Cool Bernoulli's Principle Science Experiment. Explained in kid-friendly language!
9) Video: How do Hot Air Balloons Work?