Physics Giancoli 5th Edition Ch 1-6 MIDTERM

1.2

Significant Figures

can only be as accurate as the least accurate measurement

ex. 1.06=3 sig figs, 100 = 1,2,3 sig figs, 1.00= 3 sig figs

1.2

Uncertainty Values

General area of how much the answer will vary

ex. 2.26+or- 0.25? = 11% uncertainty

Trailing Zeros do count

applied uncertainty: x/y * 100

2

Mechanics

Study of motion, composed of Dynamics and Kinematics

2

Dynamics

why objects move how they do

2

Kinematics

how objects move

2

Translational Motion

objects that move without rotating

2

Distance

how far you go

Scalar

2

Reference Frame

any measurement of position, distance, or speed must be made w/ respect to a frame of reference.

ex. train traveling 80km/h see someone walking past you 5km/h. Train as frame of reference. 80km/h + 5km/h = 85 km/h on train

any measurement of position, distance, or speed

2

Displacement

how far and in what direction

Vector

2

Speed

how fast or slow

scalar

2

Velocity

how fast or slow and in what direction

vector

Direction/Time

2

Vector

quantity that specifies magnitude and direction

velocity, displacement, force, and momentum

2

Scalar

only magnitude

mass, time, temperature

2

AVERAGE SPEED

d/t

2

AVERAGE VELOCITY

Xv2-Xv1 / Tv2-Tv1

(v means subscript)

2

Car speedometer measures?

Car Compass?

speed only (scalar)

Velocity

2

Constant Velocity

has to have a constant speed and distance

2 Table

Thank

God

Monday

Killed

Dylan

Cuz

Milli

Might (mu)

Not

12

9

6

3

-1

-2

-3

-6

-9

2

Acceleration

Anytime you change your velocity

Avg Acceleration = change in v / time elapsed

2

If acceleration and velocity are in opposite directions what happens

it decelerates

2

Who wins the race

greatest speed crossing the finish line?

person w most avg speed and velocity wins

2

can there be northward velocity and southward acceleration

slowing down acc in southward direction

2

Kinematic equations for constant acceleration

1.v=vo+at

2. xo+vot+1/2at^2

3.v^2= v^2o +2a(x-xo)

4.v (with line on it) = (v+vo) /2

1,2 involve time

2,3 involve distance

frick the fourth one tho

3

Inertia

object will keep going the same speed as long as nothing comes in contact changing motion

3

An arrow

which way and how fast

3

Tail to tip method

pic

3

Parallelogram method

pic

3

what is v sub x

the horizontal component of the v

3

Projectile motion

Constant velocity horizontally

no acceleration

ignore air resistance

gravity down

3

Horizontal kinematic equations for constant acceleration in 2 dimentions

Vertical ʻʻʻ

Horizontal

Vox=vx

x=xo+vox(t)

Vertical

Vy= voy-(g)(t)

y=yo+voy(t)-1/2g(t)^2

Vy^2=Voy^-2g(y-yo)

v(with line over)y = (vy+voy)/2

3

Parabolic trajectory

pic

4

Force

force as push or pull on an object

objects fall because of force of gravity

ex. may push on heavy desk but it may or may not move

measure magnitude- spring scale

vector

4

Newtons 1st Law

every body continues in its state of rest or of uniform speed in a straight line unless acted upon by a nonzero force

if an inertial reference frame must have no acceleration and follow 1st law

4

Why do you have to push harder on the pedals of a bike than when its already moving?

because of kinetic friction

and as you begin pedaling IT IS harder to move a body from rest

1st Law wants it to stay at rest

4

Acceleration of a body is zero, are no forces acting on it?

can be at rest or at a constant acceleration/velocity

4

inertia

tendency of an object or body to stay in its constant state of motion

4

Newtonʻs 2nd Law of motion

acceleration is directly proportional to the net force acting on it and is inversely proportional to its mass. The direction of the acceleration is in the direction of the net force acting on the object

a= {f / m

{f=ma

4

Newtonʻs 3rd Law of Motion

Whenever one object exerts a force on a second object, the second exerts an equal and opposite force on the first

relationship between two bodies

4

Intertial frame of reference

any frame that is moving at a constant velocity

earth is one (kinda it accelerates so little we donʻt even feel it)

4

something rolling. why?

dunno, but inertia keeps it going

4

Zero net force=?

staying at rest

4

Zero Acceleration=?

Keeps moving

4

thaeiajiogaehg

the one w the ball and 2 strings pic

4

Normal forces

contact force that acts perpendicular to the surface of an object Pic

FvN

4

weight of an object?

mg

4

Freebody diagram

a geometric shape that represents the objects/body of interest

4

Newton

force, 1kg x M/s^2

4

Net force

is the vector sum of all forces acting on the object

4

Kinetic Friction

sliding friction. Kinetic is moving friction.

4

Static Friciton

Refers to a force is parallel to the two surfaces that can arise even when they are not sliding.