M2.2 Flashcards
What does an atomic number denote
Number of protons
What does atomic mass consist off
Protons and neutrons
What is fluid resistance
It occurs when a solid object travels through a liquid or gas, or when a liquid travels through a solid. This causes resistance to motion within the fluid
What is viscosity
It’s the measure of a fluids resistance to flow
What happens to a liquids viscosity if temperature increases
The viscosity of a liquid decreases rapidly with an increase in temperature. Whereas a gas increases with an increase in temperature
What is a vibration
Refers to the mechanical oscillations about an equilibrium point
What is a desirable vibration compared to an undesirable vibration
Necessary for correct functioning of various devices like a loud speaker. But undesirable as it could be an imbalance like an unbalanced wheel
What is free vibration
When a mechanical swing is set off with an initial input and then allowed to vibrate freely at its natural vibration unless it damps down.
Forced vibration
When a continuous vibration or motion is applied to a mechanical system. The frequency of the vibration depends on the force applied. Whereas the amplitude (height) of mechanical system
What is a harmonic
Harmonics are periodic frequency’s. Repeats itself at standard intervals. Can be described as sinusodual with constant amplitude.
Does a harmonic wave have a positive frequency
Yes. Harmonics have a positive integer followed by fundamental frequency’s - the lowest frequency in the periodic wave.
What is a fundamental frequency
One wave that doesn’t change its integer. The first harmonic of a harmonic series.
What is the equation for a wavelength of an harmonic
Wavelength = 2 divided n (index of harmonics) x length of the body
What is resonance
The tendency of a system to oscillate at a maximum amplitude when applied force equal or at its natural frequency.
What is velocity ratio
It’s how far the effort (force push or lift) has to move in relation to the load.
If the object has a velocity ratio greater than 1 then the distance moved by the effort is greater than the distance moved by the load.
What is the equation for velocity ratio
Velocity ratio = sin (distance in) divided sin sout (distance out)
What is mechanical advantage
The ratio of the force produced by a machine to the force applied to it. Used to access performance.
What’s the equation for MA
MA = resistance(N) divided Effort (N)
What is actual mechanical advantages (AMA)
The ratio of output over input. shows how much easier work can be done.
AMA = F out divided F in
What is ideal mechanical advantages (IMA)
Shows what would exist if there was no friction on machine.
IMA = sIn divided sOut (s being distance)
What is a first class lever
The fulcrum is located between the effort and the resistance (load). FLE. middle.
Increasing distance from effort to the resistance (load) increases advantage provided by lever. When effort is applied it acts in the opposite direction to resistance. Oppositing moment either side of fulcrum.
E x L = R x L
What is a second
Fulcrum is at one end of lever and effort is applied at opposite end - wheelbarrow. The mechanical advantage is the same with 1st and 2nd lever. Only difference is the resistance and effort on first class lever act in same direction.
Third class lever
Always at the end with effort in the middle and load at the end. Landing gear attaches to aircraft which acts as a piviot point.
Inclined planes
A plane surface inclined to a horizontal plane at any angle but a right angle. Advantage as it allows large resistance to be moved yet small effort.
F1 x S1 = F2 x S2