25 terms

# Conceptual Physics - Chapter 4: Newton's 1st Law

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

#### Terms in this set (...)

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
------------
Time
Average speed =
total distance covered
----------------------------
time interval
Acceleration =
change of velocity
-----------------------
time interval
Acceleration (along a straight line) =
change in speed
---------------------
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!
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