With the new year approaching, the passage of time is on people’s minds.
Breakfast, Lunch, or Dinner?
Just as team member Malcolm is finishing a meal, he notices the minute hand is on a minute mark exactly one minute ahead of the hour hand.
Which meal is Malcolm finishing?
The 2018 Puzzle
The coach has an interesting problem to celebrate the coming year.
“You have 2018 distinct points in space. Prove that there is a plane that divides the points into two sets, with 1009 points on each side of the plane.”
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Solutions to week 119
Solar Cap Versus Polar Cap answer explained:
Let the compass radius be r. On a sphere of radius R the area of a spherical cap of half-angle θ is 2π(1 – cosθ)R2 (θ is shown in the figure.) Also from the figure, cosθ = 1 – 2sin2(θ/2) = 1 – 2r2/(2R)2. Putting these together gives the area of the spherical cap as πr2, independent of R.
How Tall Is the Pole answer explained:
Let h be the height of the pole. r = 20996000 feet is the earth’s radius of curvature, and d is the extra length of chain needed to accommodate the pole. Then, from the figure,
d = 2r(tanθ – θ) = 2r(θ3/3 + 2θ5/15 + …) ≈ 2rθ3/3
h = r(secθ – 1) ≈ rθ2/2 = (9d2r/32)1/3 ≈ 180.749… feet.
Another way to solve the problem is to use elementary trigonometry and the trigonometric equation solver found here: http://www.wolframalpha.com/widgets/view.jsp?id=27b8624af4f632acc36d65c4a7eb715.
Links to all of the puzzles and solutions are on the Complete Varsity Math page.
Come back next week for answers and more puzzles.