Unit 6 Periodic Motion Flashcards
What is the period?
Time taken to complete one rotation in seconds.
What is frequency?
The number of revolutions per second in Hz.
What is angular speed?
The angle turned through per second in rads^-1.
If an object is in uniform circular motion, what conclusions can you draw from the object?
The object has a constant linear speed but a constantly changing velocity due to the object continuously changing direction. Therefore the object must be accelerating.
If an object is accelerating and is in uniform circular motion, what is this acceleration called and where is it directed towards?
This acceleration is called the centripetal (acts towards the centre of the circular path) acceleration and is perpendicular to the direction of the linear speed.
What is centripetal acceleration caused by?
Caused by a centripetal force of constant magnitude that also acts perpendicular to the direction of motion (towards the centre) so the centripetal acceleration and force acts in the same direction.
What is angular speed (⍵) of a body in circular motion is defined as?
The rate of change in angular displacement with respect to time is measured in rad s^-1.
How can you calculate angular speed (⍵) of a body ?
⍵ = Δθ/Δt where Δθ is the change in angular displacement.
What is centripetal acceleration defined as?
The acceleration of an object towards the centre of a circle when an object is in motion (rotating) around a circle at a constant speed.
If an object is moving in a circle, is it moving in equilibrium?
No, it is not moving in equilibrium, as it has a resultant force acting upon the object which is known as the centripetal force and is what keeps the object moving in a circle.
What is centripetal force defined as?
The resultant force towards the centre of the circle required to keep a body in uniform circular motion. It is always directed towards the centre of the body’s rotation.
For a vehicle going over a hill, what is its centripetal force?
For a vehicle going over a hill, what is its centripetal force?
What is the maximum speed at which a vehicle can stay in contact with the road?
V = sqrt(gr)
For a vehicle on a banked track, what is its centripetal force?
mv^2/r = Nsin(theta)
What is the velocity of a vehicle on a banked track?
v^2 = grtan(theta)