PHYS Module 2 Flashcards

speed is the rate of…

distance traveled

speed is a ____ because it just has a ______

scalar because it just has a magnitude

velocity is…

displacement over time

velocity is a _____ because it has __ _____ _____ ___ __ _____

a direction associated with its speed

SI unit for velocity is…

m/s (meters/seconds)

average value

the value over a large interval of time

instantaneous value

the value at one particular moment in time

all frames of reference are assumed to be

stationary even if they’re technically not (earths movement)

plane problem (ground speed)=

air speed ± jet stream

(boat speed)=

speed of boat - speed of water

boat moving across the stream:

a² + b² = c²

(trigenometry)

average acceleration is

the rate at which velocity changes

deceleration

when an object slows down its acceleration opposite to the direction of its motion

instantaneous acceleration

the acceleration at a specific instant in time

average acceleration equation

SI unit for acceleration is

m/s²

delta (Δ) means

(final) - (initial)

t has no subscript in x-direction because…

time is scalar

big equation #1

v = v₀+at

big equation #2

s =(v₀)(t) + ½ a(t²)

big equation #3

v² = (v₀)²+2as

5 possible variables in kinematics

v, v₀, a, t, & s (aka Δx or Δy)

v stands for

final velocity

v₀ stands for

initial velocity

a stands for

acceleration

t stands for

s stands for

each equation has _ variables

4

each equation is missing…

ONE variable that cannot be in the equation

step one

sort what you’re given and what you’re asked for

step two

rearrange equations to unknown variable before plugging in values

step three

use sig figs, label units, identify directions on all vectors

free fall motion

motion of an object where the only force acting on it is gravity

without air resistance any falling object accelerates toward the ground at…

9.81 m/s

when an object is falling the value is…

-9.81 m/s because gravity is negative

-9.81 m/s can be used to describe…

anything that’s falling due to free fall

velocity is just ____ ___ _ _______ whereas acceleration is ___ _____ __ _______

speed with a direction, whereas acceleration is THAT change in velocity

if an object is dropped its initial velocity is…

zero

if an object is thrown upward, the sign for the initial velocity is…

positive

at the top of its path, a projectile stops for one moment, meaning its velocity is…

zero

horizontal motion and vertical motion are…

independent of one another

the time it takes to go up and down it takes to travel…

the entire sideways path

x-direction acceleration with projectiles is…

a_x= 0

y-direction acceleration with projectiles is…

a_y= -9.81 m/s²

to solve a diagonal problem the diagonal must become…

the hypotenuse of a right triangle

a right triangle is composed of…

a horizontal and a vertical leg

the legs of a right triangle are…

component vectors

component vectors make up the…

actual vector

sin(θ) = opposite ÷ hypotenuse

sin(θ) = v_y ÷ v

cos(θ) = adjacent ÷ hypotenuse

cos(θ) = v_x ÷ v

tan(θ) = opposite ÷ adjacent

tan(θ) = v_y ÷ v_x

x component vector equation

v_x = (v)(cos(θ))

y component vector equation

v_y = (v)(sin(θ))

0°

east (+x)

90°

north (+y)

180°

west (-x)

270°

south (-y)

displacement

change in position

xf

x in final position

x_i

x in initial position

x0

x naught when time = 0

Δx is the

displacement in x direction = x-x₀

resultant vector

sum of all the vectors