







Revolutions per minute 
20141024 

From Edward: Hello; I have a 28.2 inch diameter tire; do not worry about engine RPM or gear ratios, please tell me what the RPM
of that tire is at 8 MPH and 64 MPH. Thank you.
Sincerely; Edward Answered by Penny Nom. 





Angular speed 
20140629 

From andrea: a wheel having a radius of 10cm rotates such that the linear speed at its rim is 30mls.
what is the angular speed of the wheel in rpm? Answered by Penny Nom. 





Miles per minute to miles per hour 
20130908 

From Adam: Convert 250 miles per min to miles per hour Answered by Penny Nom. 





Minutes and seconds 
20120829 

From Casey: I have to write a variable equation. The questions says there are 60 seconds. but we need to write and equation to solve for minutes. Is it 1/60 or 1/s Answered by Robert Dawson. 





How many rpm does a 3.5 in. diameter wheel turn at 7 miles per hour? 
20111206 

From Al: how many rpm does a 3.5 in. diameter wheel turn at 7 miles per hour Answered by Penny Nom. 





Angular speed 
20101212 

From Jason: 7 in. pulley traveling @ 175ft/sec. What is the rpm? Answered by Stephen La Rocque and Penny Nom. 





Hours minutes and seconds 
20101126 

From beket: I need to turn 1.486588292 into real time hours minutes and seconds. I keep getting multiple answers. Online conversions give me 1 hour 29 minutes and either 11 or 12 seconds. On the calculator I get 1 hour 29 minutes and 20 seconds. Can you explain how to turn this decimal into time? Answered by Robert Dawson and Penny Nom. 





The distance travelled by a minute hand 
20100306 

From Patric: How much distance will the minutes hand of length 14mm of a clock
cover in moving from 5 to 10? Answered by Penny Nom. 





A minute hand 
20091105 

From Pardha: A minute hand of table clock is 3cms long. How far its tip move in 20 minutes Answered by Penny Nom. 





The current in a river 
20080612 

From Joi: To approximate the speed of the current of a river, a circular paddle wheel with radius 4 feet is lowered into the water. If the current causes the wheel to rotate at a speed of 10 revolutions per minute, what is the speed of the current? Express your answer in miles per hour. Answered by Harley Weston. 





1 mile per minute 
20080401 

From jennifer: If you are traveling at 1 mile per minute how fast would you need to be going Answered by Stephen La Rocque. 





How long will it take to pump the water out of the basement? 
20080401 

From Shiva: I need to pump water out of a flooded basement, using two 50 (gpm) pumps. The basement has the dimensions shown and is flooded to a depth of 16 inches. How long will it take to pump the water out of the basement? Answered by Harley Weston. 





Is there a practical use for radian measure? 
20071026 

From Paula: Is there a practical use for radian measure in any profession? Which professions might us radian as opposed to degree measure? Answered by Harley Weston. 





Metres per minute to miles per hour 
20070920 

From Angela: If a person is traveling 150 meters per minute, what is their speed in miles per hour? Answered by Stephen La Rocque and Harley Weston. 





How many gallons per minute? 
20070912 

From Diane: HI
I have a natural water spring and I am trying to determine how many gallons per minute will flow in an 8" pipe? I know one gallon is 231 cubic inches and V=nr2h  so if i had one foot of 8" pipe it would hold 2.6 gallons but I'm looking for the flow rate of how many gallons per minute? Thanks for your help. Answered by Stephen la Rocque. 





The number of minutes in n hours 
20070828 

From sharquea: the number of minutes in n hours Answered by Leeanne Boehm and Stephen La Rocque. 





Angular speed 
20070118 

From Cristina: A car is moving at a rate of 50 miles per hour, and the diameter of its wheels is 2.5 feet. a) Find the number of revolutions per minute the wheels are rotating. b) Find the angular speed of the wheels in radians per minute. Answered by Stephen La Rocque. 





What size pulley would I need? 
20061229 

From Chris: If I have a motor that's spinning at 950 RPM's with a pulley that's 6in diameter with a belt running to a generator, What size pulley would I need on the generator to make it spin at 3600 RPM Answered by Penny Nom. 





How old would i be in minutes 
20060809 

From Mariah: i would like to know how old would i be in minutes if i was thirteen years old including leap years Answered by Stephen La Rocque. 





Nine minutes 
20040902 

From A student: You have two hour glassesone measures 7 minutes and one measures 4 minutes.How can you time 9 minutes? Answered by Penny Nom. 





The hour hand and the minute hand 
20031217 

From Minnie: When you are looking at the clock at 12:00 the hour hand and minute hand are exactly together. (one on top of the other). Between 1:00pm and 1:15pm there is another time when the hour and minute hands are exactly together again. Answered by Penny Nom. 





A rock on a string 
20031026 

From A student: a rock on a 4' string is rotated at 80 rpm. what is the linear speed in feet per second? in miles per hour? Answered by Penny Nom. 





60 seconds in a minute 
20011011 

From Andy: I am a fourth grade teacher. Yesterday my students asked "Why are there 60 seconds in a minute?" Which also led to 60 minutes in an hour? I have had trouble determining why the number 60? Any help would be appreciated. Answered by Penny Nom. 





A phone bill 
20010618 

From Janet: What is the formuala to calculate cost per minute? Here is the data below # of calls  238 # of minutes  443 cost  $70.06 Answered by Penny Nom. 





Law of cosines 
20010220 

From Emily: I missed a few days of class and I can't figure out how to solve Law of Cosines problems. I have the notes and formulas but I can't figure out how to do the math involved to answer the problems. I am also getting confused about how to use degrees and seconds in the Law of Sine and Cosine. I can't seem to get the correct answers and I don't really know how to solve them and enter them into my TI 86. Answered by Harley Weston. 





PreCalculus 
20000809 

From Angela: Use absolute values to define the interval or pair of intervals on the real line.
<  ]    [ >
18 19 20 21 22 23 24 25 26
A car is moving at the rate of 50 miles per hour, and the diameter of its wheels is 2.5 feet. a) Find the number of revolutions per minute that the wheels are rotating. b) Find the angular speed of the wheels in radians per minute. Answered by Harley Weston. 





Calculs de minutes en heures 
20090223 

From Denis: Je suis en train de suivre un cours en navigation maritime et je dois changer
souvent des minutes en heures. ex: 495 minutes = ?h??
Je désire avoir le cheminement le plus simple a faire pour ce type de calcul.
Je ne travail pas avec excell. Je veux une formule a faire seulement avec
une calculatrice élémentaire. Merci pour votre aide, j'apprécie beaucoup
votre coup de main. Denis. Answered by Claude Tardif. 





calcul heures et minutes 
20080608 

From cadare: je n'arrive pas à comprendre et resoudre mes problèmes d'heures et de minutes,ex parti à 22h30, j'arrive à 7h15 quelle est la durée du trajet Answered by Claude Tardif. 





Combien d'heures et de minutes 
20070530 

From masson: pouvez vous m'aider pour resoudre ce probleme car je suis perdue
combien d'heures et de minutes dormez vous si vous vous couchez a 22h15 et si vous vous levez a 6h57?
car en suivant le raisonnement de la soustraction d'heure je trouve 15h12 et je trouve cela pas logique merci d'avance de votre aide Answered by Claude Tardif. 





addition et soustraction des heures, minutes, secondes 
20061122 

From Halnais: 13 h. 25 mn + 18 h. 06 mn 23 h. 31 mn + 19 h. 33 mn
je ne me souviens plus très bien de ces opérations, fautil additioner les heures à part puis les minutes, etc. pour les heures je crois qu'il ne faut pas dépasser 24 h. Pourriezvous m'aider, et me donner le résultat, merci infiniment. Answered by Claude Tardif. 





convertir une duree en heure et minute 
20050112 

From Sébastien: pouvez vous me donner la formule permettant de convertir une duree en heure et minute precise
pour exemple : 589 minutes donne 10h35min. Quelle serait donc la formule pour passer directement de 589 min a 10h35 (sans avoir 9h81)? Answered by Claude Tardif. 

