Dimensional analysis.ppt

A N D M E T R I C S

DIMENSIONAL ANALYSIS

THIS IS HOW I FEEL WHEN I HEAR “DIMENSIONAL ANALYSIS”

SO JUST TELL ME WHAT TO DO!

1. KEEP THIS INFORMATION HANDY

Three bases: Meter,Liter, Gram Add in a prefix:

2. GIVE ME JUST ONE REASON!

MORE TO THE POINT:

BUT:

Prefixes save1. Work2. Energy3. Time

REMEMBER THE PREFIXES?

We use them like this:

How? How?We need a relationship!

This is One wayBut anotherusefulWay is On the Next slide.

EXAMPLES OF CONVERSIONS AND DIMENSIONAL ANALYSIS

• 1. look at units and see if you can cancel all the ones on the top and bottom:

cl ml mg Mm km mi ml mm N

km mi mm km kg cl ml ml mg

2. Use your prefix chart to put numbers in front of theseUnits.

17 km x ______m x _______cm = __?___ km m Cancel out units until you cannot cancel anymore. Multiply across the top and divide by the bottom.

What isLeft?

TRY AND TRY AND TRY!

56 Mm x _____m x ______Gm = ______ Mm m

35 m x _____km x ______s = ______ s m hr

Put in the numbers and solve:

ITS POSSIBLE I CAN GET THIS!

Set up one by yourself:

2345.5 km = ? cm

1. Write the left side2. put an x and a line3. Put the unit you start withOn The bottom. Keep going.Cancel. Multiply. Divide.

2345.5 km x ___ m_

kmx ____cm m

103

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10-2= 2.3455 x 108 cm