Forces of Flight
This force pulls an airplane downward toward Earth.
Weight (gravity).
A plane is flying forward. Which direction does drag act?
Backward, opposite the plane's movement.
This force pushes upward on an object placed in water.
Buoyant force.
Water is a liquid. Air is a gas. Both are examples of this scientific term.
Fluids.
This traditional tool uses a flexible bow and string to launch a projectile.
Bow and arrow.
This force pushes upward and opposes weight during flight.
Lift.
A plane begins to climb higher into the sky. What happens to its altitude?
Its altitude increases.
This force pulls a rock downward when it is dropped into a lake.
Weight (gravity).
A student folds a piece of paper into a device that can glide through the air. What has the student constructed?
A flying device (paper airplane).
This tool uses stretched elastic material to launch a small object.
Slingshot.
This force acts against an airplane's movement through the air.
Drag.
A parachute opens and a skydiver slows down. Which force has increased?
Drag (air resistance).
An object floating still on the surface of water has a buoyant force that is _____ its weight.
Equal to.
A student wants to compare whether different objects float or sink. Name one thing they should keep the same to make it a fair test.
The liquid being used, the testing procedure, or another controlled condition.
This tool has been used by different cultures to catch fish, sometimes by throwing or thrusting it into the water.
Fishing spear.
An airplane's engines provide this force to help it move forward.
Thrust.
A paper airplane slows down as it travels through the air. Name the force responsible and explain why.
Drag, because air resists the airplane's movement.
A boat has a weight of 40 N and an upward buoyant force of 25 N. What will happen?
It will move downward because weight is greater than buoyant force.
A wide, hollow boat can carry cargo even if it is made from a material that would sink as a solid lump. Explain why.
Its shape allows it to displace enough water for the buoyant force to balance its total weight.
A bow launches an arrow forward. Name two forces that affect the arrow after it leaves the bow.
Weight (gravity) and drag (air resistance).
A plane is flying straight and level at a constant speed. How are the four forces balanced?
Lift equals weight, and thrust equals drag.
A plane has 800 units of thrust and 500 units of drag. What will happen to its forward speed if those forces stay the same?
Its forward speed will increase because thrust is greater than drag.
A boat carries more and more cargo. Explain how it can continue floating even though its weight increases.
The boat sinks deeper into the water, displacing more water and increasing the buoyant force until it balances the increased weight.
A student tests two boat designs but changes the shape, material, and cargo amount all at once. Why is it difficult to tell which change helped?
Because several variables were changed at once. A controlled experiment should change only one variable at a time.
Traditional hunting and fishing technologies were developed and improved through observation and experience. Explain how understanding forces could help someone improve one of these tools.
For example, adjusting an arrow's shape to reduce drag, designing a spear for better accuracy, or changing a bow's design to launch arrows more effectively.