Forces Flashcards
Learn the scientific Language used in the Forces unti
Air resistance
A force that resists an object’s motion through air
Air resistance is a contact force that is caused by the push of air particles.
Applied force
A force exerted by a person, animal or machine
When a girl kicks a ball, an applied force acts between her foot and the ball.
Balanced Force
A force with an equal and opposite force acting on the same object
Balanced forces cancel out and do not change an object’s motion.
Contact Force
Any force that can only occur when two objects are touching
Applied forces and friction are examples of contact forces.
Elastic Force
A force that occurs when a springy object is squashed or stretched
Elastic force is a contact force that causes a spring to return to its natural length.
Force
A push or pull
A force can make something move, stop, speed up, slow down, change direction or change shape.
Friction
A force that resists an object’s motion
Friction is a contact force. It is larger on rough or sticky surfaces.
Gravitional Field
The space around an object where its gravity is felt
On Earth’s surface, the force of the gravitational field is about 10 N for every 1 kg mass.
Gravity
An attractive force between any two objects that have mass
Gravity is a non-contact force that pulls objects to the ground or keeps them in orbit.
Kilogram
The standard unit of mass
An object with a mass of 1 kg on Earth also has a mass of 1 kg on the Moon.
Magnetism
A force exerted on some metals, such as iron and nickel
Magnetism is a non-contact force that can be either attractive or repulsive.
Mass
The amount of matter in an object or substance
The mass of an object does not depend on gravity. Mass is measured in grams or kilograms.
Net Force
The overall force on an object
The net force is found when balanced forces are cancelled out.
Newton
The standard unit of force
Named after Isaac Newton. 1 N is roughly the force of an apple pressing down on your hand.
Non Contact force
Any force that can occur even when two objects are not touching
Gravity and magnetism are examples of non-contact forces.
Spring Balance
A scientific instrument used to measure forces
The distance that the spring stretches is related to the force pulling down on it.
Tension
A force that pulls inward when a solid object is stretched
Tension is a contact force that can prevent a stretched rope from breaking.
Unbalanced force
A force without an equal and opposite force acting on the same object
Unbalanced forces change an object’s motion or shape.
Weight
The force of gravity on an object
Weight depends on mass and gravity. A 1 kg mass weighs 9.8 N on Earth but only 1.6 N on the Moon.
