







Solar cells 
20180212 

From karla: Solar (photovoltaic) cells convert sunlight directly into electricity. If solar cells were 100% efficient, they would generate about 1000 watts of power per square meter of surface area when exposed to direct sunlight. With lower efficiency, they generate proportionally less power. For example, 10% efficient cells generate 100 watts of power in direct sunlight. Suppose you want to supply 22 kilowattss of power to a house by putting solar panels on its roof. For solar cells with the average power of 49 watts per square meter of solar panels, how many square meters of solar panels would you need? Assume you can make use of the average power from the solar cells Answered by Penny Nom. 





Speed in kilometers per hour 
20171221 

From Cody: if a train travels 400 meters in 30 seconds how many kilometers per hr is it traveling Answered by Penny Nom. 





How many kilometers to a longitudinal degree? 
20140619 

From cherrielyn: Assuming that earth is a sphere of radius 6380 km,
what is the difference in the latitudes of two cities 270 miles apart
positioned on the same meridian?
Thank you in advanced po! :) Answered by Robert Dawson. 





The difference in the latitudes of Lynchburg and Myrtle Beach 
20120126 

From Sarah: Assuming that the earth is a sphere of radius 6378 kilometers, what it is the difference in the latitudes of Lynchburg, Virginia and Myrtle Beach, South Carolina, where Lynchburg is 400 kilometers due north of Myrtle Beach? Answered by Robert Dawson. 





The difference in latitudes of two cities 
20120118 

From Renee: Assuming that the earth is a sphere of radius 6378 kilometers, what is the difference in latitudes of two cities, one of which is 600 kilometers due north of the other? Answered by Robert Dawson. 





Converting kilograms to cubic metres 
20100716 

From Ilai: I want to convert kg to cubic metre Answered by Penny Nom. 





Miles per hour to kilometers per second 
20090217 

From Tamara: If a car goes 60 miles in an hour how many kilometres will it go in a second? Answered by Penny Nom. 





650g+2kg+195g=how many kg 
20081211 

From christian: 650g+2kg+195g=how many kg Answered by Penny. 





Metres and miles 
20080818 

From Bill: I enter a race that is 10,000 meters long,how many miles do i have to run? Answered by Victoria West. 





Kilometers per liters to miles per gallon 
20080626 

From margaret: we travelled 130 kilometers on 10 liters of gas. How many miles to the gallon did I get Answered by Penny Nom. 





Watts and kilowatts 
20080623 

From Kenneth: Hello:
Here is my question:
Find the kilowatthours of electricity used by a light bulb with a rating of 60 watts if the light is used for 10 hours. Answered by Stephen La Rocque and Harley Weston. 





How many meters/kilometers/millimeters would that be? 
20080117 

From chantal: if a ocean/lake/river is 250meters from where you are, how long would it take to get to shore? how many meters/kilometers/millimeters would that be? Answered by Penny Nom. 





Converting mass and volume of water 
20070510 

From Shian: Hello please help, I just can't seem to get the convertion thing and my mom tried to help but I still don't get it. How many grams does 1 milliliter of water weight? I was told 1g. How many grams does 0.1 liter of water weight? I was told 0.1g. Can you tell me if the answers given are correct with an explaination that I can understand? Thank you. Answered by Stephen La Rocque. 





Centimeters to cubic meters and grams to kilograms 
20070214 

From Colleen: A box of balls measures 120cm by 20cm by 20cm and weighs 48 g. One thousand boxes = x cubic meters and weighs x kilograms. Also, one million boxes = x cubic metes and weighs x kilograms. One billion boxes = x cubic meters and weighs x kilograms. Solve for x. Answered by Stephen La Rocque. 





Kilowatts and Horsepower 
20061103 

From Michael: How many Kilowatts=1 Horsepower or Horsepower=1 Kilowatt? Answered by Stephen La Rocque. 





A metric prefix table 
20040307 

From April: Can you tell me what the scale is for nano, micro, mega, kilo, etc.... I know that mega is 10 to the sixth power but I can't remember the other ones. Answered by Penny Nom. 





A radio controled car 
20030608 

From Robert: I have a radio controled car (scale size 1/43). This car can travel 490 ft. per minute. I would like to know how fast that is at that scale size in miles per hour (and Kilometers per hour)? Answered by Penny Nom. 





______cm=0.048km 
20030227 

From Antonette: ______cm=0.048km Answered by Penny Nom. 





Kilometers to miles 
20021009 

From A student: how many miles are in 16 kilometers? Answered by Leeanne Boehm. 





A million sheets of 30 cm long paper 
20020915 

From Jennifer: if you put a million sheets of 30 cm long paper end to end, how many kilometer long would the paper be from begining to end? Answered by Penny Nom. 





The 20 kilometer walk 
20020820 

From A student: THE 1996 OLYMPIC GOLD METAL WINNER FOR THE 20 KILOMETER WALK WAS JEFERSON. HIS TIME WAS 1HOUR, 20 MIN,AND 7SECONDS. HIS TIME WAS NOT GOOD ENOUGH TO BEAT THE WINNER IN 1988 BY JOSEF. HIS TIME WAS 1 HOUR,19 MIN, 57 SECONDS. WHAT WAS THE WALKING RATE OF EACH PERSON? Answered by Penny Nom. 





Conversion of units 
20020429 

From Matt: I am having trouble finding a workable equation for the following problem, particularly the conversion of two systems of measurement. The question states that there are 27 grams of salt in a kilogram of seawater. And it asks how many tonnes (1 tonne = 1000 kilograms) of salt are there in one cubic kilometer of ocean. It also says that the density of seawater is 1.1 g/cm3. What is the equation and how do I figure out how many kilograms there are in a cubic kilometre? Answered by Harley Weston. 





Miles and kilometers 
20020122 

From Dennis: I'm in the middle of purchasng a vehicle and it was built in Canada. Therefore it is in kilometers and not in miles. I forgot how many kilometers are in a mile. It registers as 183,049 kilometers. Answered by Penny Nom and Judi McDonald. 





Metric units 
20011025 

From Kelly: i am helping my kids out with school work and don't remember meters,centimeters decimeters and all those. We have to change meters into cm.....and so on..........is there a place on the web to look for some kind of help in these questions Answered by Penny Nom. 





300 pounds 
20010912 

From Cassie: HOW MANY KILOS IS IN 300 POUNDS? Answered by Penny Nom. 





Conversions 
20010124 

From Tanya: I have 2 questions  covert 628 kilometers to miles.(round off your answer to two decimal places.)
 a new clerk in your office is to earn $200 per week. If she works 30.5 hours each week, what is her hourly rate? (round off your answer to the nearest hundreth, that is, to the nearest cent.)
Answered by Penny Nom. 





Converting Metric Measurements 
19990408 

From Rick: Do you have any simple explanations for converting Metric measurements to other Metric measurements?? What helpful hints do you also have for a 5th Grader... Answered by Penny Nom. 





Nickles on the Highway 
19980922 

From Ronnie Mac Donald: How many nickels would it take to cover 226km of highway,each nickel is 2cm in diameter? Answered by Penny Nom. 

