Physics I Exam 1 Chapter 1-3 terms

Physics

Physika-Aristotle, study of nature/of matter and energy

Theory

something that hasn’t been disproven

Units

standardized way to measure quantities

What are some examples of Units?

Mass, time, distance, temperature

SI/MKS

Meters, Kilograms, Seconds, Celsius

CGS

Centimeters, Grams, Seconds, Celsius

Significant Figures

how many digits you reliably know in a number/measurement

Scalar

magnitude or quantity

Scalar examples

speed, mass, distance (length), energy

Vector

magnitude and direction

Vector examples

velocity, momentum, force, acceleration, position in space

Speed: Scalar or Vector?

Scalar

A mass: Scalar or Vector?

Scalar

distance (length): Scalar or Vector?

Scalar

energy: Scalar or Vector?

Scalar

Velocity: Scalar or Vector?

Vector

Momentum: Scalar or Vector?

Vector

Force: Scalar or Vector?

Vector

Acceleration: Scalar or Vector?

Vector

Position in space: Scalar or Vector?

Vector

All unit vectors have a magnitude that equals…

1

Kinematics

describes motion of things (position, velocity, acceleration)

Dynamics

how forces influence motion

What branch of physics is Kinematics and Dynamics known for?

Mechanics

Average Speed

the distance traveled divided by the time required to cover the distance

Total distance traveled / total time

Average velocity

the displacement divided by the elapsed time

x_f-x₀ / t_f-t₀

Instantaneous velocity

indicates how fast the car moves and direction of motion at each instant of time

Acceleration

a change in velocity is combined with the time during which the change occurs

Velocity is a change in…

position

Acceleration is a change in…

velocity

Constant acceleration is…

velocity changing at the same rate

The 4 kinematic equations

Trig sin equations

Trig cos equations

Trig tan equations

Law of cosines

Law of sines

How to find the Magnitude of a vector

You must break it up into its x and y (and z) parts. You can only add like vectors:C=A+B= (A_x+B_x)x^+(A_y+B_y)y^+(A_z+B_z)z^

What is the magnitude of a vector?

The magnitude of a vector is the length of the vector. The magnitude of the vector a is denoted as ∥a∥

r₀

initial position (kinematics in 2D)

r_f

final position (kinematics in 2D)

∆r

r_f - r₀

Sinθ =

opposite over hypotenuse (a/c)

Cosθ =

adjacent over hypotenuse (b/c)

Tanθ=

opposite over adjacent (a/b)

Inverse sin

θ=sin^-1(a/c)

Inverse cos

θ=cos^-1(b/c)

Inverse tan

θ=tan^-1(a/b)

volume of a cylinder

V= (π)r²h

Circumference of a circle

2(π)r