Applied Physics 11 Speed. Common Units Distance/Displacement Meter (m) Time Seconds (s) Minutes...
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Applied Physics 11 Speed. Common Units Distance/Displacement Meter (m) Time Seconds (s) Minutes (min) = 60s Hours (h) = 60 min, 3600s Days (d) = 24h Years
SpeedTo calculate speed, you need to know both distance and
timeObjects that travel at different speeds move different
distances in the same amount of timeSpeed can be calculated by
dividing the distance an object travels by the time it takes to
cover the distanceThe formula for finding speed is Speed =
distance/time v=d/t
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Unitdecicentimillimicronanobillionsmillionsthousandshundredstenstenthshundredthsthousandthsmillionthsbillionths2
types of speedYour average speed is the calculated measure of your
speed over a distance.vav= total distance/total time of tripYour
instantaneous speed is your speed at any particular instant.Not
affected by previous speed, time travelled.Constant SpeedIf
instantaneous speed remains the same over a period of time, we say
it is travelling with constant speed.Cruise controlAt constant
speed, the average speed is the same as the instantaneous
speed.
Average SpeedWhat is an average?vav= d/ t = change in d/ t =
change in distance/ change in timeFinding average speedd= 10mt=
2sv=?
v=d/tv=10m/2s
v=5m/sPhysics problemsWrite down what you know.Write down what
you are looking for.Decide which equation to use.Problem #1Chris
runs to school, a total distance of 4.5km. He has to slow down
twice to cross busy streets, but overall the journey takes 0.62h.
What is Chris average speed during the trip? d= 4.5km t= 0.62hVav=
?Vav= d/ tVav= 4.5km 0.62h
Vav=7.3km/hProblem #2Jeff is trying to predict how much time is
needed to ride his bike to the beach. He knows that the distance is
45km/h. He will have to slow down to climb hills but he knows he
will average about 20km/h. How long should his trip take? d=
45kmVav= 20km/h t= ?Vav= d/ tt=d/vavt= 45km 20km/h
