Math Minute Answers – Week 2
Thanks to everyone who submitted answers for last week’s minutes. Congratulations to the winner, Phillip, who was chosen by random number from the submissions. Lots more math to come, so if you didn’t win this week, keep calculating!
Monday: We’ve finished coring U1382A! Overall, our core recovery was 33.3%. One core was drilled from 113.3 to 122.9 mbsf and returned 6.0 m of core. What was the recovery percentage for that particular core?
122.9 m – 113.3 m = 9.6 m
(6.0 ÷ 9.6) x 100 = 62.5%
We recovered 62.5% of the core on that section.
Tuesday: The depth where we are currently installing the CORK is 4494 mbrf (meters below rig floor; the rig floor being 11 m above sea level). Pressure at sea level is 1 atmosphere, and it increases 1 atm for every 10 m of water depth. How much pressure will be exerted on the CORK head when in is in place at the bottom?
4494 mbrf – 11 m = 4483 m depth
4483 m ÷ 10 atm/m = 448.3 atm
1 atm + 448.3 atm = 449.3 atm
There will be 449.3 atmospheres of pressure exerted on the CORK at the seafloor.
Wednesday: My office is on the Fo’c’s’le Deck (one deck above the Main, two decks below the Bridge). Every day when I make my mocha, I have to go down to the Main Deck to get the milk, up to the Bridge Deck to use the fancy espresso machine, back down to the Main Deck to get it topped with whipped cream, and then back up to my office to enjoy it while looking out over the beautiful blue Atlantic Ocean. If each deck is separated by 14 stairs, how many stairs do I have to travel to make my mocha?
(down) 1 + (up) 3 + (down) 3 + (up) 1 = 8 flights of stairs
8 flights x 14 stairs/flight = 112 stairs
I have to run up/down 112 stairs to make my mocha every day!
Thursday: The camp boss has packed a total of 12,982 pounds of meat (beef, chicken, lamb, pork and fish) for Expedition 336. 3,510 pounds of that is beef, 2,891 pounds of that is chicken, 477 of that is lamb and 3,622 of that is pork. How much of that is fish?
12,982 lbs – 3,510 lbs – 2891 lbs – 477 lbs – 3622 lbs = 2,482 lbs
The camp boss packed 2,482 pounds of fish.
Friday: We started tripping pipe (running the drill string down to the seafloor) at 0200 (2:00 AM). If it takes 3 minutes to connect each stand of pipe and we needed 150 stands to reach the seafloor, approximately what time did we hit bottom?
150 stands x 3 min/stand = 450 minutes
450 min ÷ 60 (min/hr) = 7.5 hours or 7 hours, 30 minutes
0200 + 7.5 hrs = 0930
We should have hit bottom at 0930 (9:30 AM).