5.2 Circular Motion Flashcards
what is a radian
a radian is an angle subtended by a circular arc eith a length equal to the radius of the circle
How many radians is there in a full circle
2π radians
How can an angle be converted from degrees to radians
Divide by 360 then multiply by 2π
What is a period in circular motion
Time in seconds taken for an object to travel a full circle
What’s the frequency in circular motion
The number of full circles completed in one second
What’s angular velocity ω
The rate of change of angle
What formula is ω given by
ω= θ/t
the angle the object has travelled through in the time t
Whats angular frequency / velocity measured in
rads^-1
What is the equation for angular frequency
ω=2π/T =2πf
What is centripetal force
The net force which acts perpendicular to the direction of the velocity towards the centre of the circle
Why is there a centripetal force
-When an object travels in a circle the direction is constantly changing
-velocity is a vector so it is also changing
-as velocity is changing there must be an acceleration
-this acceleration is provided by the centripetal force
What is the equation for the speed of an object v moving in a circle or radius r
v=2πr/t = ωr
What’s the equation for centripetal acceleration
a= v^2/r = ω^2r
What equation is used for the centripetal force acting on an object
F=mv^2/r =mω^2r
What is the centripetal force on an object when there’s multiple forces acting on an object moving in a circle
The resultant force acting on the object
What are examples of how centripetal force can be provided
-Gravitational fields
-friction
-tension in a rope
How can circular motion be investigated experimentally
