The acceleration of a body in a circular motion. Its direction is towards the centre of the circle
a=rω^2 a=v^2/r
What is the centripetal force?
the force on a body in circular motion. Its direction is towards the centre of the circle
F=mrω^2 F=mv^2/r
What is a simple harmonic motion?
Any motion where the acceleration of a particle is proportional to the product of the masses and inversely proportional to the square of the distance between them
a∞-s
What is hooke's law
the restoringforce on a spring is proportional to the extension of the spring.
F=-ks
What does anybody with a circular motion have?
linear velocity and angular velocity
Define angular velocity
ω=θ/t
the angle passed through each second
What is a period (T) of a particle in circular motion is given by w
T=2pi/ω
What is the centrifugal force?
A force that pullsaway from the centre of the circle and is known
What is the moment of a force?
an axis is equal to the magnitude of the force multiplied by the perpendicular distance from the axis to the line of action of the force
(tells us the ability to make something turn)
moment=f*d
How does a doorknob open a door
Use the handle located as far from the hinges as is reasonable.
For a small force, this creates a large moment or turning effect
e.g crowbar is an example of a lever that makes maximum use of a force to move a heavy object
Couple
created by two parallel forces with the same magnitude acting in opposite directions.
Give an example of a moment?
the handlebars of a bike.
one hand moves forward, the other back, and the couple created turns the handlebar, and with it the bike
What are the conditions for equilibrium
1. the sum of the forces in any direction equals the sum of the forces in the opposite direction
2.the sum of the moments equals any point is zero.