Further Mechanics Flashcards
Define Simple Harmonic Motion
Oscillation where acceleration is directly proportional to its negative displacement
Which way is acceleration directed
Always towards the equilibrium
Define Forced Vibrations
When periodic force is applied the frequency is determined by the frequency of the driving force
Resonance
Occurs when the frequency of applied force= natural frequency, it produces vibrations of large amplitude as maximum energy is transferred
Damping
When force opposes the motion and removes energy
Free Vibration
System displaced and left to oscillate
How does damping affect the resonance
Reduces sharpness of resonance and reduces amplitude at the resonant frequency
For a mass-spring what is the resultant force acting on the mass composed of
Composed of its weight and the tension in the spring system
Where is velocity greatest
At the equilibrium where x=0
Where is acceleration greatest
When x is greatest therefore when x=A
Which way does damping act
Opposite direction to velocity
Name 3 types of damping
Lightly damped, Heavily damped and Critical
What are the 2 types of potential energy involved in a mass-spring system
gravitational Potential and Elastic Potential
Define Angular Speed
The angle turned per unit time, measured in rads-1
Define Radian
The angle subtended at the centre of the circle by an arc that is equal in length to the radius
Why is car driving round a roundabout at constant speed accelerating
- Because velocity is a vector, and because its direction is constantly changing , its velocity is always changing, therefore it must have acceleration
- Newtons first law states that an object remains at rest or continues at constant velocity unless acted on by a resultant force. This means that because it has a force acting towards the centre of the circle
Which way is centripetal acceleration always directed
Towards the centre of the circle
What is centripetal force
It is the name given to the resultant force acting towards the centre of the circle, it itself is not a physical force
In a pendulum what is the centripetal force provided by
The horizontal component of tension
For a car on a banked track what contributes to the centripetal force
Horizontal Component of normal reaction force and lateral friction
When is the velocity of a pendulum in SHM greatest
When the pendulum is at its equilibrium
When is the acceleration of a pendulum in SHM greatest
When the magnitude is greatest
What is the only way to alter the time period of a pendulum
Alter the length
What is the total energy of a free oscillation, and how does it change
Sum of the potential energy and kinetic energy, and is constant throughout the oscillation
