Forces Flashcards
(34 cards)
What are forces
Forces are actions that change an objects current motion
What is acceleration
An increase in an objects movement speed
What is deceleration
A decrease in an objects movement speed
What are newtons
Newtons are used to measure force, 1 newton is equivalent to the force needed to move a one kilogram object at one metre per second
What is Issac Newtons first law
An object at rest, or in constant motion, will remain that way unless acted on by another force
Drawing Forces
Force diagrams are used to indicate both the direction and strength of a force. The length of the arrow indicates the strength of a force, the longer the arrow, the stronger the force.
What is a balanced force
When there are two forces acting in opposite directions that are of equal force, then the forces are said to be balanced
What is an unbalanced force
When oppositely acting forces are of unequal force, they are said to be unbalanced
Net force
Net force is the sum of the forces acting on an object, forces that are opposite cancel each other out
Inertia
The resistance of an object to any change in motion
How do cars save people from the force of crashes
Cars use seatbelts to hold the passenger on the seat and crumple zones to absorb the energy
What is friction
Friction is the force that occurs when one object tries to move across another. It is a contact force
What are factors that affect friction
How rough a surface is, how hard the surfaces are pushed together
What are someways friction is useful
Running, cars and busses move can stop faster, allows us to hold things in our hands
When is friction not useful
It can create heat and energy like when you fall and you scrape your knee
Reducing Friction
Friction can be reduced by separating the surfaces or smoothing surfaces out
Gravity
The attractive force that exists between objects containing matter and is an non-contact force
Mass and Weight
Mass is the amount of matter in an object (kg), Weight is the force experienced by an object due to Gravity (N)
Acceleration due to gravity
The acceleration due to gravity is constant for all objects regardless of mass
Acceleration due to gravity is 9.8m/s/s
All objects fall at the same in a vacuum (no air)
Terminal Velocity
The highest speed that an object can fall through air
The force due to gravity is matched by the air resistance caused by air particles
Magnetism
A non-contact force of attraction and repulsion
It is part of the electromagnetic force
Magnetism is caused by the motion of electric charges
Magnetic Fields
The area around a magnet that will apply a force
The arrows of a magnetic field diagram demonstrate the force experienced by a north pole within the field
Attraction and Repulsion
Like poles repel
Unlike poles attract
Magnetic Domains
Certain materials have magnetic fields generated by the movement of their electrons
Large groups of atoms are able to line up parallel to each other
These groups of atoms are known as Magnetic Domains
With enough magnetic domains lined-up, a material may possess a strong overall magnetic field
