25 terms

Conceptual Physics 10th e. by Paul G. Hewitt
Summary of Terms, Summary of Formulas, and Terms Within the Textbook

Speed

How fast something moves; the distance traveled per unit of time.

Velocity

The speed of an object and a specification of its direction of motion.

Vector quantity

Quantity in physics that has both magnitude and direction such as velocity

Acceleration

The rate at which velocity changes with time; the change in velocity may be in magnitude, or direction, or both.

Free Fall

Motion under the influence of gravity only.

Speed =

Distance

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Time

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Time

Average speed =

total distance covered

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time interval

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time interval

Acceleration =

change of velocity

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time interval

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time interval

Acceleration (along a straight line) =

change in speed

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time interval

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time interval

Velocity acquired in free fall, from rest;

*v = gt*

elapsed time

the time that has passed since the beginning of any motion, in this case the fall.

Relative Motion

All motion is relative to the observer and the reference point used.

Linear motion

Motion along a straight-line path.

Instantaneous speed

Speed at any instant. example: speedometer

Constant velocity

Motion in a straight line at a constant speed.

Average velocity

final velocity plus initial velocity divided by 2

Distance, velocity and acceleration vs time graphs

Graphs which plot distance, velocity and acceleration against the independent variable of time .

Know the relationships!

Know the relationships!

The two measurements necessary for calculating average speed are

Distance and time

A car maintains a constant velocity of 100 km/hr for 10 seconds. During this interval its acceleration is

Zero

While an object near the Earth's surface is in free fall, its

velocity increases

A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is

Zero

Disregarding air resistance, objects fall with constant

acceleration

equilibrium

The state of a body in which no net force acts on it

speed vs time graph

slope represents acceleration

distance vs time graph

slope represents speed