Dynamics S3 Flashcards
SPEED
The distance travelled each second
Average speed
The total distance travelled by an object at a particular moment in time
Instantaneous speed
The speed of an object at a particular moment in time
Acceleration
The change in speed each second. It is given by the gradient of the line on a speed-time graph
Deceleration
A negative acceleration which indicates that an object is slowing down
Force
An interaction between two objects that can change an object’s shape, speed, direction. It is measured in Newtons(N)
Newton Balance
A device with a scale in newtons that can be used to measure forces
Contact force
A force applied to an object by another body that is in direct contact with it. E.g. a push, pull, twist
Non-Contact
A force applied to an object by another body that is not in direct contact with it. E.g. gravity, magnetism or electrostatic
Friction
A force which opposes the motion of an object
Air resistance
A frictional force caused by air particles coming into contact with an object
Balanced forces
When the forces acting on a object are equal in magnitude but opposite in direction
Unbalanced forces
When the forces acting on an object are different in magnitude but opposite in direction
Mass
The quantity of particles that make up an object. It is measured in kilograms(kg)
Weight
The force due to gravity acting on an object. It is measured in newtons (N)
Gravitational Field Strength
The gravitational force per unit mass. On Earth, g is 9.8Nkg
Newton’s 1st law
An object will remain at rest or move at a constant speed in a straight line unless acted on by an unbalanced force
Newton’s 2nd law
The forces acting on an object are unbalanced, the object will accelerate in the direction of the unbalanced force
Free-fall
Describes the movement of any object under the influence of gravity alone
Terminal Velocity
For an object in free-fall, a constant speed is reached when the upward force on the object(air resistance) is balanced by the downward force on the object(weight)
Newton’s 3rd law
I f an object A exerts a force on object B, then B exerts an equal but opposite force on A
Newton Pairs
Action and reaction forces for a specific situation involving Newton’s 3rd law
