Chapter 1: Units and Kinematics Flashcards
Number of liters in a gallon:
3.785
How to multiply numbers in scientific notation:
multiply significands, add the exponents
How to divide numbers in scientific notation:
divide significands, subtract the exponents
A number raised to a power in scientific notation:
raise the significand by the number, multiply the exponents by that number
How to add/subtract numbers in scientific notation:
The numbers have to have the same exponents. If they do not, convert one of them so that they have the same exponents.
Logarithm
the log of a number for a given base is the power to which the base must be raised to equal that number. In other words, a base raised by some power will equal a number, and that power is the log of that base.
The two most common bases:
e (natural log; 2.71) and 10 (common log)
log(mn)=
log(m) + log(n)
log(m/n)=
log(m) - log(n)
log(mn)=
nlogm
Vectors are:
Numbers with magnitude and direction (e.g. displacement, velocity, acceleration, and force)
Scalars are:
Number with magnitude only and NO direction (e.g. distance, speed, energy, pressure, and mass)
The sume or difference of two vectors is called the:
resultant of the vectors
Whe adding vectors, add them:
tip-to-tail
A single vector can be broken up into:
X and Y components
Subtracting two vectors can be accomplished by:
Adding the opposite of the vector being subtracted. A - B = A + (-B). By “-B” we mean a vector with the same magnitude, just pointing in the opposite direction.
Displacement
A change in position in space. A vector quantity.
Velocity
Displacement / Time
Instantaneous Velocity
lim( t → 0) Displacement / Time
Acceleration
The rate of change in velocity over time. A vector quantity.
Acceleration results from:
an application of force
Average acceleration=
deltaV / deltaT
Instantaneous Acceleration
Defined as the average acceleration as time approaches zero.
lim ( t→0) ΔV / ΔT
On a velocity versus time graph, the tangent to the graph at any time (the slope) is the:
Instantaneous acceleration. (+ slope is + acceleration)