SHM (test) Flashcards
what does 1 rad roughly equal to
57 degrees
Angular speed
the angle of an object rotates through per second
Defined as angle / time
units = rad s^-1
equation for angular speed
w = theta / t
arc lenth equation
arc lenth = r x theta
equation for linear velcoty, v
v = arc lenth / t
v = r x theta / t
v / r == theta / t
equation for angular speed using linear speed
w = v / r
frequency
f = 1 / t
w = 2pi / t
w = 2pi x f
acceleration
the rate of change of velocity
centipetal acceleration
objects travelling in a circle are accelerating since their velocity is changing due to the fact that the the direction the object is travelling in is changing
therefore an object would be accelerating even though its not going any faster
equation for l
l = v x change in t
change in velocity equation
change in v = Vb - Va
l / r == change in v / Va == vhange in v / v
v x change in t / r == change in v / v == change in v / change in t === v x v / r ===
v^2 / r
a = vv / r as a = vhange in v / change in t
intergrate w into a = vv / r
a == ww x r
centripetal force
newtons 1st law states that an objects velocity will not change unless there is an external force acting upon it
since objects moving in a circle have acceleration, there must be a force causing the acceleration
centipetal force equation
sub f = m x a
F = m vv / r
F = m ww r
SHM can be defined as
An oscillation in which the acceleration of an object is directly proportional to its displacement from its equilibrium position and is directed towrads the equilibrium
Simple harmonic motion
An object moving with SHM oscillates to and from either side of an equilibrium position
This equilibrium position is the midpoint of the objects motion
Distance of object from equilibrium is called its displacement
restoring force
the force pulling or pushing the object back towards the equilibrium position
size of the force depends of the displacement
the restoring force makes the object accelerate towards the equilibrium
SHM rule
a is directly proportional to -x
also force is DP TO x
the minus sign shows that the acceleration is always opposing displacement
Displacement ( graph )
avries with cosine and sine wave
max value of A (amplitude)