AP Physics - Summer Overview Study

Vectors

Something w/ magnitude/size AND direction

Scalars

Something w/ only magnitude/size

If there is an item moved a certain distance, AND given direction…

it was displaced

Distance is a ______ quantity

scalar

Displacement is a __________ quantity

vector

If there is a TIME and a magnitude/size, then it is a _________ quantity

scalar, because it doesn’t have an exact direction

If a brick moved 5 m and the duration is 2 seconds, it is _________

scalar SPEED

If a brick moved 5 m N and the duration is 2 seconds, it is ___________

vector VELOCITY

Change in position (magnitude), and fixed direction =

displacement

Change in position (magnitude), but NO fixed direction =

distance

How fast something is going specified & direction =

velocity

How fast something is going, but NO direction =

speed

Is velocity a scalar or vector quantity?

Vector

velocity simple definition

Displacement over time

Constant/average velocity VECTOR QUANTITY Formula:

Displacement/Change in Time

Rate/Speed SCALAR QUANTITY Formula:

Distance/Change in Time

When you hear “magnitude” it means…

the genera size, quantity, how much or how big despite of direction (or the overall size of the movement)

With MAGNITUDES, scalar quantities have…

only magnitudes

With MAGNITUDES, vector quantities have…

both magnitude and direction

Explain the similarity and difference between rate/speed and velocity?

Both are the same thing (speed), but velocity is a vector quantity while rate is scalar. Velocity contains direction and rate does not

Instantaneous speed

speed of an object at a particular moment in time

Instantaneous Velocity

velocity of an object at a particular moment in time

Method #1 to find instantaneous velocity: If object travels at a constant velocity then…

the V(average) = V(Instantaneous)

Method #2 to find instantaneous velocity, if object travels at changing velocity then…

look at the motion on x (m) versus t (s) graph so SLOPE (AT ANY PARTICULAR POINT) = INSTANTANEOUS VELOCITY

Method #3 of finding the instantaneous velocity, if acceleration is constant then…

use the kinetic formulas: V=V(i) + at —> if you dont know displacement and V² = V(i)² +2a(delta x) —> if you dont know time

When it comes to using kinematic formulas to find instantaneous speed then you can conclude that…

the V(f) = instantaneous cause the acceleration is constant

Vector or scale quantity: Acceleration

vector quantity

What is Acceleration

Change in velocity over time

Primary formula of ACCELERATION:

Delta Velocity/time (or change in time)

If the acceleration of a moving object is constant = you can assume the velocity that is given is the average so the way you find your velocity in order to solve for example—the displacement—then…

take the average. So V(avg) = (Vi + Vf)/2

Given a groan of velocity versus time, the slope equals acceleration because…

the slope is change in y (velocity) over change in x (time), but acceleration equals just that

When the acceleration equals zero…the acceleration IS

constant

Proportionality

as one value increases, so does the other

Inverse Proportionality

as one value increases, the other decreases

Constant of proportionality

any number included in an equation that is NOT a variable (doesn’t change, is constant)

If given a problem with a constant acceleration addressed this way…"Slows down at a constant acceleration of ______”, that means the acceleration is…

a negative value

Direct Proportion GRAPH:

non-horizontal line that passes through the origin y=kx; k is the constant of proportionality and is the slope of the graph

Linear GRAPH:

non-horizontal line, y=mx+b

Quadratic GRAPH:

parabola; when y is proportional to x² , the graph goes through he origin and has a slope that increases as x increases

Inverse GRAPH

hyperbola; when y is proportional to 1/x, the graph is asymmetric to the x and y axes; y = k/x