Motion

filercaliforniaΜηχανική

14 Νοε 2013 (πριν από 3 χρόνια και 7 μήνες)

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Motion

Motion


Motion
-

the change in the position of an
object with respect to time and its
reference point



Motion is RELATIVE



Reference point/
frame of reference
:
a
point/object that is not moving

Reference Point and Relative Motion

Example:

-
If you are sitting on a train looking at your
neighbor, neither of you seem to be moving

-
If you look out the window at people standing
on the side, they seem to be moving
backwards

-
If the people on the side are looking at you,
you seem to be moving forward

Describing Motion


Distance
-

the length between two points


Units: meters, kilometers, etc.



Time


Speed



Speed
-

is the distance traveled per unit
of time


Units: m/s, km/s, etc.




S= speed

D = distance

t= time

Solve for other variables
:



D
= s*t


t= D/s


Formula
:

S
= D/t


Average Speed


The total distance divided by the total
time





Instantaneous Speed



The speed at any given instant

You must always show your
work and
units!!





ALWAYS METRICS


No answer is complete
without units!

Let’s try one!

Calculate the speed of a dog running through a field if
he is covering 23.7 meters in 54 seconds.


Given
:


Formula:



Find
:




Work
Space
:





If a cross country runner covers a distance of 347
meters in 134 seconds what is her speed?


Given:


Formula:



Find:




Work Space:




Velocity


Velocity
-

The speed and direction an object is
moving in


Units: speed and a direction


Example: The car’s velocity is 60 km/hr EAST




Try This:

Calculate the velocity of a dog running north through a
field if he is covering 23.7 meters in 54 seconds.


Given:


Formula:



Find:




Work Space: