prev

next

of 20

View

35Download

1

Embed Size (px)

DESCRIPTION

Unit Conversions. Are Units important?. 3. Are Units important?. Project Cost $327.6 million total for both orbiter and lander . $193.1 million for spacecraft development, $91.7 million for launch $42.8 million for mission operations. http://mars.jpl.nasa.gov/msp98/orbiter/. 4. - PowerPoint PPT Presentation

Unit Conversions

Are Units important? 3

Are Units important? Project Cost $327.6 million total for both orbiter and lander.

$193.1 million for spacecraft development,

$91.7 million for launch

$42.8 million for mission operations.http://mars.jpl.nasa.gov/msp98/orbiter/ 4

Are Units important? "The 'root cause' of the loss of the spacecraft was the failed translation of English units into metric units in a segment of ground-based, navigation-related mission software, as NASA has previously announced," said Arthur Stephenson, chairman of the Mars Climate Orbiter Mission Failure Investigation Board." http://mars.jpl.nasa.gov/msp98/orbiter/ 4

ConvertingInches to centimetersConvert 10.0 inches to centimeters

ConvertingInches to centimeters10.0 inWe start by writing down the number and the unit as a FRACTION1

ConvertingInches to centimeters10.0 in1 in2.54 cmOur conversion factor for this is 1 in = 2.54 cm.Since we want to convert to cm, it goes on the top.1x

ConvertingInches to centimeters10.0 in1 in2.54 cmNow we cancel and collect units. The inches cancel out, leaving us with cm the unit we are converting to.1x

ConvertingInches to centimeters10.0 in1 in2.54 cm=25.4 cmSince the unit is correct, all that is left todo is the arithmetic...The Answer1x

Even though we have two different numbersand two different units, they represent theexact same length. You can check this by looking at a ruler find the 10 in mark anddirectly across at the cm side. What numberdo you find?

A more complex conversionkm to mhr sIn order to work a NSCI 110 homework problem, we need to convert kilometers per hour into meters per second. We can do both conversions at once using the same method as in the previous conversion.

80 km1 hrA more complex conversionkm to mhr sStep 1 Write down the number and theUnit as Fraction!

80 kmhr1 hr3600 sA more complex conversionkm to mhr sFirst well convert time. Our conversion factor is1 hour = 3600 sec. Since we want hours to cancel out, we put it on the top.1x

80 kmhr1 hr3600 s1000 m1 kmA more complex conversionkm to mhr sNext we convert our distance from kilometers to meters. The conversion factor is 1 km = 1000 m.Since we want to get rid of km, this time it goes on the bottom.1xx

80 kmhr1 hr3600 s1000 m1 km=A more complex conversionkm to mhr sNow comes the important step cancel and collect units.If you have chosen the correct conversion factors, you should only be left with the units you want to convert to.ms1xx

80 kmhr1 hr3600 s1000 m1 km=80,000 m3600 sA more complex conversionkm to mhr sSince the unit is correct, wecan now do the math simplymultiply all the numbers on thetop and bottom, then divide thetwo.1xx

80 kmhr1 hr3600 s1000 m1 km=80,000 m3600 s=22.2msA more complex conversionkm to mhr sThe Answer!!1xx

80 km/hr and 22.2 m/s are both velocities. A car that is moving at a velocity of 80 km/hr is traveling theexact same velocity as a car traveling at 22.2 m/s.

Convert a rate from one unit to another with a change in both units

Convert a rate from one unit to another with a change in both units