The Four Forces of Flight

Gravity - is an invisible force which pulls objects ______.

Tags

NGSS.5-PS2-1

Lift depends on ______ - lift increases, as speed increases. Lift depends on direction - lift acts perpendicular to the direction of the

object's movement.

• weight

• speed

• height

• direction

Answer explanation

Lift depends on angle of attack - up to a point, lift increases as the angle of attack increases; beyond that point, lift is lost. Angle of attack refers to the angle ______________.

• at which the wing is tilted into the airflow.

• at which the wing is lowered into the airflow.

• at which the wing is raised into the airflow.

• at which the wing is turned away from the airflow.

Lift - is an _______ force.

Answer explanation

Lift - is an upward force. If the lift force is greater than the gravity force, the object will stay in the air. Lift depends on shape - lift will be greater with an air-foil shaped wing than with a flat one.

Drag depends on shape - a shape with low drag is usually long, thin, and smooth, rounded at the front and becomes more narrow at the back. Drag also depends on _________ - drag tends to increase as __________ increases.

Answer explanation

Drag can be useful. For example, when a parachute on a dragster opens up after the race, it creates a drag force that helps to slow the car down. Drag depends on ___________ - a ___________ with low drag is usually long, thin, and smooth, rounded at the front and becomes more narrow at the back.

Tags

NGSS.MS-PS2-2

______ - is the force that moves an airplane forward and is usually produced by a plane’s jet engines and propellor. For an airplane to take off, the engine’s thrust has to move the airliner forward faster than drag can push it back.

• Drag

• Lift

• Thrust

• Gravity

Answer explanation

Objects with a ______ mass pull and attract objects with ______ mass towards them.

Tags

NGSS.MS-PS2-4

Because the Earth has a very large mass, all objects near it are pulled ___________ its centre. This _________ “pull” is called the force of gravity and works against things that are trying to _______.

Tags

NGSS.5-PS2-1

______ is a force that slows you down and works in the opposite direction than you are traveling.

• Drag

• Gravity

• Lift

• Thrust