Mechanics Flashcards
What is VELOCITY?
VELOCITY is the rate of change of displacement
v = s/t
SI unit: m s¯¹
What is ACCELERATION?
ACCELERATION is the rate of change of velocity
a = v-u / t
SI unit: m s¯²
What is MOMENTUM?
MOMENTUM is the product of the mass and velocity of a body
p = mv
SI unit: kg m s¯¹
What is FORCE?
FORCE is the product of mass and acceleration
F = ma
SI unit: N ( = kg m s¯² )
What is FRICTION?
FRICTION is the force that opposes motion between two surfaces in contact
What is WORK?
WORK is done when a force causes a body to be displaced
W = Fd
SI unit: J ( = N m )
What is ENERGY?
ENERGY is the ability to due work
- KINETIC ENERGY is the energy a body has due to motion
K.E. = ½mv²
- POTENTIAL ENERGY is the energy a body has due to its position or state
P.E. = mgh
What is POWER?
POWER is the rate at which work is done or energy is converted
P = W/t
SI unit: W ( = J s¯¹ )
What is a RENEWABLE SOURCE OF ENERGY?
A RENEWABLE SOURCE OF ENERGY is one that will not be exhausted; eg. solar, wind, tidal, etc.
What is the EFFICIENCY OF A MACHINE?
The EFFICIENCY OF A MACHINE is the energy output as a percentage of energy input
What is a LEVER?
A LEVER is any rigid body that is free to rotate about a fixed point, called the fulcrum
What is the MOMENT OF A FORCE (TORQUE)?
The MOMENT OF A FORCE (TORQUE) is the force applied mulitplied by the perpendicular distance to the fulcrum
M = Fd
SI unit: N m
What is a COUPLE?
A COUPLE is two equal parallel forces that act in opposite directions. The moment of a couple is the magnitude of one force multipied by the perpendicular distance between them
What is SIMPLE HARMONIC MOTION?
SIMPLE HARMONIC MOTION is defined as motion where an object’s acceleration is directly proportional to its displacement from a mean position and always directed towards it
a = -ω² x
What is CENTRIPETAL FORCE?
CENTRIPITAL FORCE is the force acting towards the centre for a body moving in a circular path
F = mv²/r
