Form 4 Term 1 Physics Unit 17 Mechanics 2 Flashcards
Acceleration
The rate of change in speed is measured in metres per second squared
Deceleration
Slowing down or negative acceleration
Displacement
Quantity describing the distance from from start of journey to end of journey in a straight line with a direction
Example 50km due north of starting point
Force
Is a push or a pull
Unit of force is the NEWTON N
Magnitude
The magnitude tells us the size of the vector
Moment
A turning force around a pivot - clockwise or counterclockwise
Measure in Newton-metres Nm3 (force and distance)
Force multiplied by the perpendicular distance to a pivot
Stationary
Not moving
Velocity
The speed an object moves in a particular direction
Gravity
The force of attraction between all objects
More mass in an object means the it exerts a larger force of gravity
More mass = exerts more force of gravity
Inversely
Two variables are inversely related if one decreases when the other increases
Mass
Mass is measured in kilograms KGS
mass of an object is a measure of unwillingness of an object to change its velocity (to accelerate)
Large rock = more mass = hard to make it move quickly / gain velocity
Matter
Sub atomic particles
Oppose
When one things works against something else to reduce of eliminate effect
Example: an opposing force to a PUSH is a PULL
Frictional force
Force that resists one object moving through or over something
Example: air resistance on a car as it drives along (like when hold hand out car window)
Kinetic energy
Energy which an object possesses by being in motion
Resultant force
The single force that could replace all the other forces acting on an object
Calculated by adding all forces together.
If all forces are equal the resultant force is zero
Surface area
The total area of an object
Terminal velocity
The max speed of an object - reached when the forces moving on the object are balanced by its frictional forces.
At terminal velocity acceleration is zero (it can’t go any faster it’s at maximum)