25 terms

Forces

2012 Physics Unit Vocabulary
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speed
tells us how fast something is going. distance divided by time
velocity
tells us how fast AND which way somthing is going.
acceleration
the rate at which velocity changes
m/s
unit of speed or velocity
meters, centimeters, inches, feet
unit of distance
force
a push or pull on a object
friction
the force that opposes the motion of an object
Air resistance
A type of fluid friction
Balanced force
When the net force = 0 newtons. An object is not moving or moving at a constant velocity at this time
unbalanced force
when the net force does not = 0.
sliding friction
a force that opposes the direction of motion of an object as it slides over a surface
rolling friction
friction that occurs when an object rolls over a surface
static friction
friction that acts on objects that are not moving
fluid friction
friction that occurs as an object moves through a fluid (includes water, air)
Inertia
The tendency of an object to resist change in its state of motion
Newton's First Law
Objects and rest tend to stay at rest. Objects in motion tend to stay in motion, unless acted on by an unbalanced force.
Newton's Second Law
The acceleration of an object depends on the mass of the object and the amount of force applied. F=m*a
Gravity
the downward pull on an object on Earth
Newton's Third Law
For every action there is an equal and opposite reaction.
Newtons (N)
Unit of force
Acceleration of gravity
9.8m/s2 on earth
meters per second squared (m/s2)
unit of acceleration
kilograms (kg)
unit of mass
Vector
a quantity that has magnitude and direction
normal force
the force that a surface exerts on an object that is pressing on it