1st Quarter Perio Reviewer.docx

Physics 1 – Physics Fundamentals I Fundamental Units       

Length (m) Mass (kg) Time (s) Electric Current (A) Temperature (K) Luminous Intensity (cd) Amount of Substance (mol)

Length, Mass and Time are the fundamental units of mechanics with an additional unit: force. Significant Figures -

Are the number of reliably known digits in a number o All non-zero digits are significant o Leading zeroes are not significant o Captive zeroes (in between sig. figs.) are also significant o Trailing zeroes after the decimal are significant and otherwise are not. o When multiplying or dividing, follow the number with least number of significant figures o When adding or subtracting, follow the number with the least number of decimal places o When quantities are given in a problem, follow the datum with the least number of significant figures

Rounding Of o

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When the digit after the last position of the desired rounded number is in the range of 0 to 4, retain the number in the last position of the desired number If the digit is between 6 and 9 inclusive, then the final digit of the desired

o

number will be one added to the number in that position in the original number If the digit is 5, then the penultimate digit will become the even number above it if it is odd, and otherwise retained.

Kinematics in One Direction     

Mechanics – the study of force, energy and motion Kinematics – a branch of mechanics dealing with motion Scalar Quantity – deals with magnitude only Vector Quantity – deals with magnitude and direction Motion – change of position with respect to a point of reference o Distance – a variable of motion which defines how long an object travels in its actual path taken; a scalar quantity o Time – a scalar quantity o Displacement – how far an object is from its starting pint; the shortest distance from an object and where it came from; a scalar quantity o Speed – rate of change in distance; scalar quantity

s peed = o

v elocity=

distance time

Displacement – rate of change of displacement; vector quantity

displacement time

o

Average Speed – total distance over elapsed time

o

Acceleration – rate of change in velocity

Three Fundamental Equations in Physics

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vave = dt-1 vave = (vi + vf) t-1 a = (vf – vi) t-1

Additional Equations

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vf = vi + at d = vit + 0.5at2 vf2 = vi2 + 2ad

Motion Graphs

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Projectile Motion

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Distance-Time Graph o How far was travelled o Slope is instantaneous velocity o d-t, s-t, x-t graphs  Velocity-Time Graph o How fast the object is moving o Slope is instantaneous acceleration o v-t graph o Area under the graph is distance covered  Acceleration-Time Graph o How the velocity changes over time o a-t graph Motion Diagrams 

pictorial representations of an object I motion taken in equally spaced intervals of time

Free Fall Motion

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Galileo Galilei o an object rolling down an incline picks up the same amount of speed in successive seconds o distance travelled by uniformly accelerating object is

proportional to the square of time steeper, the incline, greater the acceleration free-fall has greatest acceleration taking in to account no initial velocity in a vacuum, all objects fall at the same time g = -9.8 ms-2 = -32 fts-2 velocity going up = velocity going down at the same y or height

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When an object is thrown horizontally on a certain height, gravity works upon it and it follows a parabolic curve with the following equations: horizontal time = vertical time = parabolic time d = 0.5at2 + vit for free fall or vertical distance covered d = vavet for horizontal distance covered