A21 Definitions Flashcards
What does Hooke’s Law state?
Hooke’s Law states that the extension of an elastic material is directly proportional to the applied load provided it is not stretched beyond its limit of proportionality.
What is the limit of proportionality?
The limit of proportionality is the maximum load that can be applied so that the extension is still directly proportional to the applied load.
What is the elastic limit?
The elastic limit is the maximum load that a body can experience and still return to its original size and shape when the load is removed.
What is plastic deformation?
Plastic deformation is when an object does not return to its original shape and size when the load is removed.
What is elastic deformation?
Elastic deformation is when an object does return to its original shape and size when the load is removed.
How is stress defined?
Stress is defined as the force acting per unit area of cross-section of the wire.
Stress = Force/Area
What is the formula for strain?
Strain = Change in length/Original length
What is Young’s Modulus?
Young’s Modulus = Stress/Strain
E = o/€
What is ultimate tensile stress?
Ultimate tensile stress is the maximum stress that can be applied to the object before it breaks.
What does Boyle’s law state?
Boyle’s law states that for a fixed mass of gas at constant temperature, the volume is inversely proportional to the applied pressure.
What does Charles’ law state?
Charles’ law states that for a fixed mass of gas at constant pressure, the volume is directly proportional to the Kelvin temperature.
What does Gay Lussac’s Pressure Law state?
For a fixed mass of gas, at constant volume, the pressure is directly proportional to the Kelvin temperature.
What is a mole?
The mole is the amount of substance which contains as many particles as there are atoms in 0.012kg of carbon 12.
What is the internal energy of a gas?
The internal energy of a gas is the sum of the potential and kinetic energy of its molecules.
What is specific heat capacity?
The specific heat capacity, c, of a material is the quantity of heat energy needed to raise the temperature of 1kg of the material by 1k.
What is angular velocity?
Angular velocity is the rate of change of angular displacement.
What characterizes simple harmonic motion?
A particle is performing simple harmonic motion if its acceleration is directly proportional to its displacement from a fixed point and is always directed towards that point.
What is resonance?
Resonance occurs when one system (the driven) is set into vibration at its natural frequency as a result of impulses received from a second system (the driver).
What are damped oscillations?
Damped oscillations occur when an oscillating system is subjected to resistive/frictional forces which remove energy from the system resulting in a reduction in the amplitude of the vibrations.
What are free oscillations?
Free Oscillations have a constant amplitude and constant period and the main factor is that they are not under any external influences.
What occurs in heavily damped systems?
No oscillations occur and the system returns very slowly to an equilibrium position.
What is critical damping?
It occurs when the damping forces allow the system to return to its equilibrium position in the shortest possible time (T/4 where T is the periodic time).
What is a forced oscillation?
A forced oscillation is when one system sets another system vibrating as a result of periodic impulses.
What are isotopes?
Isotopes are nuclei with the same atomic number but different mass number; they have the same number of protons but different number of neutrons.
