physical science exam 1

Description

lead to understanding our environment

Description involves the _______ of the physical world

measurement

Understanding our environment demands the interpretation of _____ measurements

accurate

Measurements:

movement, temperature, weather conditions, time, etc

Can everything be measured with certainty?

No, as objects get smaller and further away, it’s harder to be certain/precise with those measurements

Which sciences make up the classification of the physical sciences:

Physics, chemistry, geology, meteorology, and astronomy

Measurements are the basis of

scientific research/investigation

Scientists assume that the universe is _____ and can be understood

orderly

Scientific method is

the general methods of observations, rules for reasoning, and making predictions

Scientific method broken down into the steps:

Observations/measurements, hypothesis, experiments, theory, and law

1) Observations and Measurements:

Quantitative data are gathered

2) Hypothesis:

a possible explanation for the observations (tentative answer/educated guess)

New experiments are designed to test the validity of the _____, its supported if it correctly predicts the experimental results

hypothesis

3) Experiments:

testing a hypothesis

5) Law

after a series of experiments a concise statement (words/math) describes a fundamental relationship of nature (simply states the FINDING, but DOES NOT explain the behavior observed)

4) Theory:

a well tested explanation for a broad segment of basic natural phenomena (may be accepted, modified, or rejected)

Standard Units and Systems of Units is expressed in _____ and ______

Magnitude, Units

Fundamental quantities:

length, mass, and time

Standard Unit:

fixed and reproducible value to take accurate measurements

What are the two major system of units?

The International System of Units (SI) aka the metric system & the English system

British (English) system:

only used widely in the US (miles, inches, pounds, seconds, etc)

Metric system:

used throughout most of the world (kilometers, meters, grams, etc)

The measurement of space in any ____

direction

Space has three dimensions:

length, width, and height

For length, the Metric System Standard Unit is

Meter (m)

For length, the British Standard Unit is

Foot

Mass is the

amount of matter an object contains

An object’s mass is always ____

Constant

In terms of Mass, the Metric Standard Unit is

Kilogram (kg)

In terms of Mass, the British Standard Unit is slug, but we use

Pound (Ib)

The ____ is actually not a unit of mass, but rather of weight, related to gravitational attraction

pound

Time is the

continuous, forward flowing of events

Time only has one _____

direction

Second (s) is

the standard unit in both the metric and British systems

Metric Systems uses acronym “______” from standard units of length, mass, and time — meter, kilogram, second (decimal base-10 system)

“mks system”

Contains ____ base units

seven

What is a liter?

Volume of liquid

How does a liter compare to a quart?

Slightly more than a quart

Density:

how compact a substance is

What are the typical units used for density?

mass per unit volume

Hydrometer:

a weighted glass bulb

The ____ the hydrometer floats, the greater the density of the liquid

higher

What are derived units?

are multiples/combinations of fundamental units

What are significant figures used for?

used to express measured number me properly

When adding or subtracting quantities, the answer is limited with the fewest _____ _____.

decimal places

When multiplying or dividing, the answer is limited with the fewest ______ ______.

significant figures

The four basic rules for significant figures are:

1) All non zero digits are significant

2) Zeros between non-zero digits are always significant

3) leading zeros (to the left of the first non-zero digit are not significant

4) trailing zeros are significant if the number contains a decimal point, but are not significant if the number does not contain a decimal point

What’s the rule pertaining to rounding off numbers?

round up on 5

What are the rules for writing numbers using scientific notation?

place the decimal point after the first non-zero digit to create a coefficient between 1 & 10, then multiply by 10 raised to an exponent representing the number of places the decimal was moved.

Motion is everywhere - _____,_____,_____

walking, driving, flying

Motion is

an object is undergoing a continuous change in position

Description of Motion:

The time rate of change of the position (a combination of length and time)

Speed is

a scalar quantity, with only magnitude

A car going 80km/h is an example of ____

Speed

Velocity is

a vector, and has both magnitude & direction

A car going 80km/h north is an example of _____

Velocity

____ quantities may be represented by arrows (can be positive & negative)

Vector

A _____ _____ has only magnitude

Scalar quantity

A _____ ______ has both magnitude and a specific direction

vector quantity

Average speed is

the total distance divided by the total time elapsed

Instantaneous speed is

the speed of an object at an instant of time

Distance is

the actual path length traveled

Displacement is

a vector quantity between two points

What are the three ways changes in velocity occur?

speeding up, slowing down, and changing direction

Define Acceleration

A measure of the change in velocity during a given time period

Units of acceleration

m/s²

What’s meant by constant acceleration of 9.8 m/s²?

means that an object’s velocity changes by 9.8 m/s every second

Why is acceleration a vector quantity?

because it describes both how quickly an object’s velocity is changing (magnitude) and the direction of that change (direction)

______ refers to any rate of change in velocity like speeding up, slowing down, or changing direction, while _____ refers to the reduction in an object’s speed, meaning the acceleration is in the opposite direction of the object’s motion

Acceleration, deceleration

Explain frictional effects (air resistance)

the force of friction air exerts on an object moving through it, opposing the object’s motion and slowing it down

Explain acceleration due to gravity in the up and down direction

If upward is defined as the positive directions then acceleration due to gravity is negative because it acts in the opposite direction. If downward is defined as positive direction, the acceleration due to gravity is positive.

Explain acceleration in Uniform circular motion.

An object is constantly changing direction, even if its speed is constant

What does centripetal mean?

means center seeking (acceleration that’s pointing to the inward/center)

What’s projectile motion?

the curved path an object takes through the air when thrown or launched, and it can be analyzed by separating its horizontal and vertical motions, which are independent.

The horizontal velocity in projectile motion remains ______, because there are no horizontal forces

constant.

What angle corresponds to the maximum range of a projectile?

45 degrees

In projectile motion, the _____ velocity changes due to gravity, because it decreases on the way up, becomes zero at the peak, and then increases in the downward direction:

vertical