Physics Flashcards
Define static
When a body is at rest or all the forces are in equilibrium it is static
Define centre of gravity
Centre of gravity is the balance point of an aircraft or object
What is the equation for moments
Moment is force x distance
For an aicraft to return to equilibrium what moments have to be equal
The clockwise and anti clockwise moments
Scalar quantiles have only got
A magnitude
Vector quantities have
A magnitude and direction
What is the formula for stress
Stress is force divided by area
What is the unit of stress
N/m squared
What is the equation for strain
Strain is is the change in length divided by the original
What is the equation for elasticity
stress divide by the strain
What is hookes law hint (springs )
is the spring constant times the exstention
What parts does the stress strain curve have
Proportional limit
Elastic limit
Lower yeild point
Breaking point
Fracture point
The density equation is
Mass divide by volume Kgm cubed
What is the pressure equation
Force divide by area
What is pascals principle
It says that when force is applied to an enclosed fluid they transmit all pressure to the walls of the container equally
What is absolute pressure
Gauge pressure plus the ambient pressure usually 15
What is the effect of depth
It gets greater the further you go down due to atmospheric pressure and the water above you
How to calculate load
Pressure x area
What is Archimedes principle
It is the law of bouyncy the volume of displaced fluid is equivalent the volume of the object immersed
What is relative density
Weight of solid divide by the upthrust
Upthrust cna be calculated by the weight of the object in the air - the weight of the object in water
What is atmospheric pressure
It is effectively the column of air sitting above you stretching to the atmosphere it is about 101.3kn m cubed
How to claulate the height of a mecurcy Colum
It is pressure divide by density x gravity
How to calculate speed
Speed is distance traveled divide by time taken
Acceleration
Change of velocity divide by time
Is velocity a vector true or false
True
What is the equation of linear motion
The initial velocity plus change of velocity x time or v=u+at
What is Newton’s first law
An object at rest tends to remain at rest and an object in motion tends to remain in motion
What is Newton’s second law
When a force acts upon a body the momentum of the body is changed the rate of change is proportional to the applied force
What is Newton’s third law
Every action has an equal and oposite reaction
What is the equation for momentum
Mass x velocity
How to calculate angular displacement
Arc length divide by radius of the circle
How to calculate angular velocity hint (rads )
The angular displacement (rads) divide by time
Centripetal force acts towards the scentre true or false
True
Centrifugal force acts outwards true or false
True
What is periodic motion
It is a motion that repeats itself after an equal period of time
They at and sup of the amplitude the height of the wave
The time period peak to peak
And the displacement the lowest peak to the biggest
What is resonance
It is the natural frequency of an object if two frequency math they’ll resonate an increase their amplitude
How to calculate mechanical advantage
Force x distance
load / effort
What is a first class lever
It’s like a sea saw
What is a second class lever
It’s where is on the handle and you balancing it on the fulcrum
Effort load fulcrum
What is a third class lever
It’s where your hands in the middle closest to the fulcrum with the weight on the other side
Load effort fulcrum
How to calculate the mechanical advantage of a screw
Circumference divide by pitch
What is the velocity ratio
It is the distance moved by effort divide by the distance moved by load
Or
Teeth on driven divide by teeth on drive
What is weight
Mass x gravity
What is the equation of boyles law
P1 x v1
What is the Doppler shift equation
Reciver frequency - transmitter
What is the atomic mass
Protons and neutrons
What do the atomic number
Protons
What is acceleration
V2 -V1
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