Further Mechanics Flashcards
What is angular speed, ω?
Angular speed, ω, is defined as the angle turned, θ, per unit time.
Its units is rad s^-1
ω = θ/t (not given in exam)
ω = v/r (given in exam)
What is centripetal acceleration?
Since objects moving in a circle are constantly changing direction, they are thus constantly changing velocity, and so accelerating. (Although they are not gaining speed)
Centripetal acceleration is always directed towards the centre of the circle.
What is centripetal force?
From Newton’s Laws, we know that if there’s a centripetal acceleration, there must also be a force. This is the centripetal force.
Since F = m x a,
F = mv^2/r = mω^2r (given in exam)
What would happen if you removed the centripetal force to an object moving in a circle?
It would fly off at a tangent.
What is critical damping?
Critical damping is a form of damping that reduces the displacement of an oscillating object to its equilibrium position in the quickest time possible and without further oscillation.
Critical damping is a form of damping that reduces the ______ of an ______ object to its ______ position in the _______ time possible and without further ______.
Critical damping is a form of damping that reduces the (displacement) of an (oscillating) object to its (equilibrium) position in the (quickest) time possible and without further (oscillation).
What is damping?
Damping is the dissipation of energy from an oscillating system.
The consequence is that the amplitude of oscillation will decrease.
Damping occurs when a force opposes the system’s motion.
Critical damping is a form of damping that reduces the ______ of an ______ object to its ______ position in the _______ time possible and without further ______.
Critical damping is a form of damping that reduces the (displacement) of an (oscillating) object to its (equilibrium) position in the (quickest) time possible and without further (oscillation).
What are forced vibrations?
Forced vibrations are repeated up and down oscillations, at the frequency of a driver.
The amplitude of oscillation is small at high frequencies and large at low frequencies.
Forced vibrations are ______ _______ and _______ oscillations, at the frequency of the ______.
The amplitude of oscillation is small at ______ frequencies and large at ______ frequencies.
Forced vibrations are (repeated up) and (down) oscillations, at the frequency of a (driver).
The amplitude of oscillation is small at (high) frequencies and large at (low) frequencies.
What are free vibrations?
Free vibrations are oscillations that are not caused by a driver.
An object will naturally oscillate at its natural frequency.
Forced vibrations are ______ _______ and _______ oscillations, at the frequency of the ______.
The amplitude of oscillation is small at ______ frequencies and large at ______ frequencies.
Forces vibrations are (repeated up) and (down) oscillations, at the frequency of a (driver).
The amplitude of oscillation is small at (high) frequencies and large at (low) frequencies.
What is overdamping?
Overdamping is a type of damping where the system is damped more than required to stop the oscillations.
It takes longer for the system to return to equilibrium than for critical damping.
Free vibrations are oscillations that are not caused by a ______.
An object will naturally oscillate at its ______ ______.
Free vibrations are oscillations that are not caused by a (driver).
An object will naturally oscillate at its (natural frequency).
What is overdamping?
A type of damping where the system is damped more than required to stop the oscillations.
It takes longer for the system to return to equilibrium than for critical damping.
