Further Mechanics FM1-5 Flashcards
What is meant by ‘centripetal acceleration’?
It is the acceleration towards the centre of the centre of the circular path provided by the centripetal force. Changes in direction and not magnitude, therefore it isn’t constant.
Present when an object is moving in a circle.
What is meant by ‘centripetal force’?
It is the resultant force directed towards the centre of the motion. It is the force that causes circular motion.
What does ω represent?
Angular speeed
What does v represent?
Velocity
What does f represent?
frequency or the centripetal force
For an object in circular motion how does the angular speed change?
ω keeps the same
For an object in circular motion how does the velocity change?
v changes as the direction is constantly changing.
For an object in circular motion how does the force change?
f keeps the same into the centre of what the object is moving around, changes in the direction not magnitude sense.
For an object in circular motion how does the acceleration change?
a the magnitude doesn’t change but the direction is constantly changing so the acceleration isn’t constant.
Define the angular speed?
The angualr displacement moved thorough (in radians or degrees) per second.
What equations relate to angualr speed?
v = 2πr/T = rω;
v = rω;
T = 1/f ;
ω = 2πf;
ω = Δθ/Δt
How is the number of radians in an angle given?
θ = s/r; where s is the arc length, r is the radius and θ is the angle in radians.
How does the velocity act in a circular motion?
The velocity acts tangentially.
What are the equations relating centripetal acceleration, velocity, radius and the angular speed?
𝑎 = 𝑣^2/𝑟 = 𝜔^2r
How does the force and acceleration act in a circular motion?
Towards the centre of motion.
What is an example of a force that does no work?
Centripetal forces
What are the equations relating centripetal force, velocity, radius and the angular speed and the mass?
𝐹 = 𝑚v^2/ 𝑟 = 𝑚v^2r
When a car turns a corner, what provides the required centripetal force?
Friction
What provides the centripedal force for a car travelling along a banked track?
The reaction force between the track and the car, allowing faster speeds.
What is the centripetal force of an object travelling in a vertical circle?
The centripetal force is the difference between the upward and downward forces.
To look at the diagrams for the forces on related diagrams check on this google docs, cover up the right and think what the left would look like then check.
https://docs.google.com/document/d/1giyqLUlxALVbsJ9rU4qKjqp8PnTlwJLAvvKXlJ6vsQc/edit
When does an object feel like it experiences “apparent weightlessness”?
When the object is in free fall, the whole of his weight provides the centripetal force to maintain that velocity at that height about earth’s surface.
When looking at the collection of dust particles on a spinning disc there is a more concentrated on the inner part of the vinyl disc of dust, why?
Closer to the centre particles need smaller centripetal force.
v is directly proportional to r, or angular speed = constant along disc.
Idea that friction, electrostatic forces are sufficient to meet the requirements of particles close to the centre but not those further away.
What is the calculation used to find the angle at which a ball moves in?
distance / (2 x pi x radius)
