Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
36 Cards in this Set
- Front
- Back
A moment? |
Moment – Force multiplied by perpendicular distance between force and the pivot |
|
The principle of moments? |
States that for an object to be in equilibrium the sum of the anticlockwise moments equals the sum of the anticlockwise moments (no turning moment) |
|
An object is in equilibrium if? |
An object is in equilibrium if: The sum of anticlockwise moments = sum of clockwise moments All vertical forces cancel and all horizontal forces cancel |
|
A Couple? |
A Couple – A pair of opposite and equal forces separated by distance d, acting about point p, the turning effect at point p is equal to one of Forces multiplies by the perpendicular distance between the forces |
|
Centre of mass? |
Centre of mass – Where all of an objects mass appears to act about and moments cancel |
|
A Newton? |
A Newton – Force required to accelerate 1kg by 1ms-2 |
|
A Joule? |
A Joule – Work done 1N through a distance of 1m in direction of force |
|
Law of conservation of energy? |
Law of conservation of energy – energy is never created or destroyed just converted between different types |
|
Hooke’s Law? |
Hooke’s Law – The extension of a spring is proportional to the force applied to it as long as the limit of proportionality is not exceeded |
|
Stress? |
Stress – Force per unit area |
|
Strain? |
Strain – Ratio of extension to original length |
|
Young’s Modulus? |
Young’s Modulus – Stiffness constant of a material |
|
A longitudinal Wave? |
A longitudinal Wave – a propagating wave with oscillations in the same direction as propagation/energy transfer |
|
A transverse wave? |
A transverse wave – A propagating wave with oscillations perpendicular to the direction of propagation |
|
A stationary wave? |
Stationary wave – Formed when 2 waves of similar frequency travelling in opposite directions interfere and the resultant wave is the vector sum of each waves displacements at that point by the principle of superposition |
|
Diffraction? |
Diffraction – Spreading out of a wave when passed through a slit of around an obstacle |
|
Coherent Sources? |
Coherent Sources – Same frequency and constant phase relationship |
|
Constructive Interference occurs when? |
Constructive Interference occurs – 2 waves intersect and interfere through principle of superposition and the resultant displacement I the vector sum of the 2 waves displacement at that point and the phase difference between the 2 waves at that point is a whole number of wavelengths (destructive when 180 degrees phase difference – half number of wavelengths) |
|
Differences between single and double slit diffraction? |
Differences between single and double slit diffraction: Single – Wide central maxima 2x width of others and reduction in intensity going away Double – Same intensity same width going out |
|
Newton's First Law? |
Newton's First Law- A body will state in the state of rest or Uniform motion unless acted upon by an external unbalanced force/resultant force |
|
Newton's Second Law? |
Newton's Second Law- F=ma Force is directly proportional to the mass |
|
Newtons Third Law? |
Newtons Third Law - Action force is always equal to the reaction force but always in the opposite direction |
|
Define Freefall? |
Freefall is defined as the motion of an object undergoing an acceleration of 'g' |
|
What is friction? |
Friction is a Force which opposes motion |
|
What is work? |
Work is the amount of energy transferred from one form to another when a force causes movement of some sort |
|
What is power? |
Amount of energy transformed from one form to another per second |
|
If forces stretch the material they are? |
If forces stretch the material they are tensile |
|
If forces squash the material they are? |
If forces squash the material they are compressive |
|
Waves - Displacement? |
How far a point on the wave has moved from its undisturbed position |
|
Waves - Amplitude? |
Maximum displacement |
|
Waves - Wavelength? |
The length of one whole wave from crest to crest |
|
Waves - Period? |
The time taken for a whole vibration? |
|
Waves - Frequency? |
The number of vibrations per second passing a given point |
|
Waves - Phase difference? |
The amount by which one wave lags behind another wave, measured in radians or degrees |
|
A progressive wave? |
A progressive wave carries energy from one place to another, without transferring any material |
|
A standing wave? |
A standing wave is the superposition of two progressive waves with the same wave length, moving in opposite directions |