Required Recall (Courtesy of Jack) Flashcards
What are the 7 SI units and quantities?
Length - meter (m) Time - second (s) Amount of substance - mole (mole) Electric current - ampere (A) Temperature - kelvin (K) Luminous intensity - candela (cd) Mass - kilogram (kg)
It is stated after the measurement as ±
For example 48 ± 0.5 kg, 21.4 ± 0.05s, 105.43 ± 0.01N, 6 ± 0.8J
How do we work out the absolute uncertainty?
A) When we do have a range of values
B) When we do not have a range of values
A) If we have a range of values the absolute uncertainty is half the range of values.
B) If we do not have a range of values the absolute uncertainty is half the resolution of the measuring instrument.
_____ 10^12 1 000 000 000 000 trillion
_____ 10^9 1 000 000 000 billion
_____ 10^6 1 000 000 million
_____ 10^3 1 000 thousand
tera T 10^12 1 000 000 000 000 trillion
giga G 10^9 1 000 000 000 billion
mega M 10^6 1 000 000 million
kilo k 10^3 1 000 thousand
_____ 10^-3 0.001 thousandth
_____ 10^-6 0.000 001 millionth
_____ 10^-9 0.000 000 001 billionth
_____ 10^-12 0.000 000 000 001 trillionth
milli m 10^-3 0.001 thousandth
micro u 10^-6 0.000 001 millionth
nano n 10^-9 0.000 000 001 billionth
pico p 10^-12 0.000 000 000 001 trillionth
The formula for the area of a circle and volume of a sphere.
area of circle = πr^2
volume of sphere = 4/3 πr^3
State the definitions for scalar and vector quantities and give examples of each
scalar = has a magnitude, temperature vector = has direction and magnitude, Velocity
Label the quantities shown by the slopes and areas of distance-time, velocity-time, and acceleration-time graphs
distance/time: slope shows speed and area shows total displacement.
velocity/time: slope shows acceleration and area shows total distance
acceleration/time: slope shows acceleration at that point and area shows the change in velocity
if an object is thrown at 16ms at an angle of 40 to the horisontal, resolve for the horisontal and vertical components.
horisontal = 16cos(40) =12.26
vertical=16sin(40)=10.28
State Newton’s Laws of motion
Newton’s first law states that an object will stay at constant velocity unless acted upon by an unbalanced force.
Newton’s second law, F=ma
Newton’s third law is that when a force is exerted on an object a directly opposite force thats equal in magnitude occurs on the object.
State the properties of pairs of forces in an interaction between bodies
The size of the force on the first object equals the size of the force on the second object. The direction of the force on the first object is opposite to the direction of the force on the second object.
State the principle of conservation of linear momentum
If no external forces act on two colliding objects, then the vector sum of the linear momentum of each body remains constant
State the definition of ‘the moment of a force’
the moment of a force is the total sum of it’s clockwise and anti-clockwise rotational forces
State the principle of conservation of energy
the total energy of an isolated system remains constant
State the definition for current
charge per unit time (rate of flow of charge)
Derive the equations for combining resistances in series
V1=IR1, V2=IR2 Vt=V1+V2+V3 Vt=IR1+IR2+IR3 V=I(Rt) Rt=R1+R2+R3
Derive the equations for combining resistances in parallel
Vt=V1=V2=V3 It=I1+12+I3 I1=V/R1, I2=V/R2,=I3=V/R3 I=V(1/R1+ 1/R2+1/R3) 1/Rt = 1/R1+ 1/R2+1/R3
State the definition of electromotive force (e.m.f.)
energy per unit electric charge that is imparted by an energy source
decribe the structure of a metal
atoms arranged in a regular patterns with a sea of delocalised electrons
describe laminar and turbulent flow
laminar flow = the flow of a liquid with streams parallel to eachother.
turbulent flow = the flow of liquid with streams that cross and go back on themself
State the conditions in which Stoke’s Law applies
a smooth sphere moving through laminar flow with constant velocity and tempreture
State the relationship between upthrust and displaced fluid
the upthrust on an object in a fluid is equal to the weight of the fluid displaced
Define the term limit of proportionality
the force at which hooks law no longer applies
Define the term elastic limit
the point at which additional force will permanently disfigure a material
Define the term yield point
the stress beyond which a material deforms plastically
What is the difference between elastic and plastic deformation
Elastic deformation is when the material will return to its original shape.
Plastic deformation is when the deformation is irreversible
the quantities shown by the slopes and areas of a force-extension graph
Slope = spring constant
Area = work done
the definitions of transverse and longitudinal waves
transverse = the waves movement perpendicular to its propogation
longditudional =the movement of the wave is parallel to its propogation
State the definition of amplitude
the maximum displacement of an oscillation
State the definition of wavefront
when all the points on a wave have the same phase
State the definition of coherence
waves are coherent if they are constantly in phase
State the definition of path difference
the difference in the distance between two waves.
nλ = in phase,
(n+0.5)λ = out of phase
State the definition of superposition
the resultant displacement at the point multiple waves meet
State the definition of interference
when multiple waves of the same frequency cross and combine their vector displacement
State the definition of phase
a specific point on a wave in relation to that same point on the same type of wave
definition standing wave
when a waves profile doesn’t move and only oscilates up and down
difference between a node and anti-node
a node has zero amplitude while the anti-nodes have the maximum amplitude.
difference between real and virtual image
A real image iswhen the rays of light meet at a point whereas a virtual image is formed when the rays of light meet at a point in the ‘minds eye’
State the definition of plane polarisation and give examples of its use
When only one frequency of wave is allowed through a screen. This can be used to block uv rays in sunglasses by only allowing visible light.
definition of diffratcion
Diffraction is when waves spread out a as they pass through a gap or move around an object
Describe diffraction experiments that provide evidence for the wave nature of electrons
single electrons were fired through a diffraction grating and onto a detector. The pattern on the detector showed interference which cant be explained with partical physics.
The formula for the area of a trapezium.
area of a trapisium= (a+b)/2 *h
