Mechanics Flashcards
What is the Symbol and Units of Displacement?
Symbol: S
Units: m
What is the Symbol and Units of Initial Velocity?
Symbol: u
Units: ms^-1
What is the Symbol and Units of Final Velocity?
Symbol: v
Units: ms^-1
What is the Symbol and Units of Acceleration?
Symbol: a
Units: ms^-2
What is the Symbol and Units of Time?
Symbol: t
Units: s
What is the gradient of a Displacement-Time graph?
Velocity
What is the gradient of a Velocity-Time graph?
Acceleration
What is the area of a Velocity-Time graph?
Displacement
What is the area under an Acceleration-Time graph?
Velocity
What are the five SUVAT equations?
v = u+at s = vt-0.5at² s = ut+0.5at² s = t(u+v)/2 v² = u²+2as
When are SUVAT equations applicable?
When the acceleration is constant
What is Projectile Motion?
It is a simplified way to understand and calculate the motion of an object.
It models horizontal and vertical motion as independent
What is assumed with Projectile Motion?
Air ressistance is ignored
It is in a uniform field
The initial velocity is imparted instantaneously
Vertical and horizontal motion is independent
What is Newton’s First Law of Motion?
An object will remain at rest or continue to move with a constant velocity, unless acted upon by a resultant force.
What is the Resultant Force?
The Overall force acting upon an object
What is Newton’s Second Law of Motion?
The force acting on an object is product of the mass and the acceleration
What is Newton’s Second Law of Motion as an equation?
F = ma
What is Newton’s Third Law of Motion?
Every action has an equal and opposite reaction acting upon a different object.
When is Newton’s Third Law of Motion true?
It is true for all situations
Not just equilibrium
What is Terminal Velocity?
It is the constant speed reach in free fall
When is Terminal Velocity reached?
When Weight = Ressistance
What is the equation the links Work Done, Force and Displacement?
Work Done = Force x Displacement in direction of the force
w = Fs
Is Work Done Scalar or Vector?
Scalar
What is the equation for Kinetic Energy?
Energy = 0.5 x Mass x Velocity² E = 0.5mv²
What is Kinetic Energy proportional to?
E ∝ m
E ∝ v²
What is the equation for change in Gravitational Potential Energy?
Energy = Mass x Gravitaional Field Strength x Change in height E = mgΔh
Define Power?
The rate of work done
Or
The rate of energy transfer
What is the Symbol and Units of Power?
Symbol: P
Units: W
What is the equation that links Power, Force and Velocity?
Power = Force x Velocity P = fv
What is the equation that links Power, Work Done and Time?
P = w/t
Define Efficiency?
The ration of Useful Output Power to Total Input Power
What is the equation of Efficiency?
(Useful Output Power / Input Power) x 100
Or
(Useful Output Energy / Input Energy) x 100
What is the equation for Momentum?
Momentum = Mass x Velocity p = mv
Momentum = Force x Time p = Ft
What is the Symbol and Units of Momentum?
Symbol: p
Units: Ns
What is an Elastic Collision?
A collision where no energy is lost
What is an Inelastic Collision?
A collision where energy is lost
What is Change in Momentum?
Impluse
What are the equations for Impulse?
Change in Momentum = Force x Change in Time
Δp = FΔt
Change in Momentum = Mass x Change in Velocity
Δp = mΔv
What is the area under a Force-Time graph?
Impulse
For an object to be in Static Equilibrium it has to what?
Have no resultant force
Therefore no acceleration
What is the Moment of a Force?
The rotaional force acting on an object
What is the Symbol and Units of Moment of Force?
Symbol: T
Units: Nm
What is the equation for calculating a Moment of a Force?
Moment = Force x Perperndicular distance between force and pivot T = Fm
What does the Principle of Moments state?
If a body is in rotaional equilibrium, the total clockwise moment is equal to the total anticlockwise moment
Σ↻ = Σ↺
