Mechanics Flashcards
What is the difference between scalars and vectors?
A scalar quantity only has magnitude, not direction, but with a vector quantity you need to state the direction as well as the magnitude.
Examples of scalar quantities
Distance, Speed, Mass, Volume, Energy, Power, Time, Temperature, Potential difference. Resisitance
Examples of vector quantities
Displacement, Velocity, Acceleration, Force, Momentum, Weight, Electric field strength, Intensity,
Prefixes for: nano, micro, milli, kilo, mega, giga
(nano, n, x10^-9) (micro, u, x10^-6) (milli,m, x10^-3) (Kilo,k, x10^3) (mega, m, x10^6) (giga, g, x10^9)
What is Newton’s first law of motion?
States that an object will remain in a state of rest or continue to move with a constant velocity unless acted upon by a resultant external force
What is Newton’s second law of motion?
F=MA The acceleration of a body of a constant mass is proportional to the resultant force applied to it and in the direction of the resultant force
What is Newton’s third law of motion?
If body A exerts a force on body B, body B will exert an equal and opposite force on body A.
Talk about displacement time graphs
The gradient is the velocity
Talk about a velocity time graph
The gradient is the acceleration, the area between the line and axis is the displacement
How do you calculate horizontal and vertical components?
Sin is for vertical, cos for horizontal
What is the principle of conservation of energy?
Energy is never created or destroyed, but can be transferred from one form to another by work
What is Velocity
The speed of an object in a given direction
What is acceleration
An object’s ability to gain speed
What is gravitational field strength
The gravitational force exerted by the Earth on a mass of 1kg.
What is meant by centre of gravity
When all the gravitational force acts on a single point,
What is meant by work done
When a force acts on an object and transfers energy.
What is meant by power
The rate at which work is done. rate at which energy is transferred WORKDONE/TIME
What is meant by gravitational potential energy
Its related to change in height mgh
What is the principle of conservation of energy
Energy can be neither created nor destroyed, but it can be transferred. Total energy at start=total energy at end.
What is meant by density
Mass per unit volume kgm^-3
What is terminal velocity
When the resultant force of a falling object is 0, there is no acceleration. UPTHRUST + VISCOUS DRAG=WEIGHT
What does stoke’s law give
Formula for viscous drag for a small sphere at low speeds in laminar flow
Graph for brittle
[//////// [//// [/// [// [/---------------------
Graph for ductile
[////////------\ [////// [//// [/// [/---------------------
