Physics: Speed Physics: Speed and Velocityand Velocity

Average SpeedAverage SpeedRate at which an object Rate at which an object movesmoves

Units are in distance / timeUnits are in distance / timeEx. Meters/second, Ex. Meters/second, centimeters/hourcentimeters/hour

Units of DistanceUnits of DistanceMiles (mi)Miles (mi)Centimeters (cm)Centimeters (cm)Feet (ft)Feet (ft)Light year (Ly)Light year (Ly)Meters (m)Meters (m)

Units of TimeUnits of Time

Seconds (s)Seconds (s)Hours (hr)Hours (hr)Minutes (min)Minutes (min)Years (yr)Years (yr)

Equation for Equation for Average SpeedAverage Speed

Speed = Speed = d/d/t = t = change in change in distance/change in distance/change in timetime

VELOCITYVELOCITYVelocity is speed with a Velocity is speed with a directiondirectionEx. A car is traveling Ex. A car is traveling 12 mph west12 mph west

V = V = d / d / t = change in t = change in position/ change in timeposition/ change in time

Uniform MotionUniform Motion

Motion at a constant speed Motion at a constant speed and directionand direction

Also called “constant Also called “constant velocity”velocity”

Instantaneous Instantaneous SpeedSpeed Speed of an object at a particular Speed of an object at a particular

moment or “instant” of timemoment or “instant” of time Ex. Reading on a speedometerEx. Reading on a speedometer

Graphs of Speed/ Graphs of Speed/ VelocityVelocity

Constant velocityConstant velocity Slope gives you velocitySlope gives you velocity

Speed Graphs cont’dSpeed Graphs cont’d Increasing SpeedIncreasing Speed

d(m)

t(s)

A

Object is not moving, speed is 0