A train is traveling 50 at 50 knots and a dolphin is swimming at 20 miles per hour, who makes to shore first?
350753
wather train?????\ninteresting
810640
See picture: http://mudandmuck.com/str2/BOAT.JPG\nShe must travel √(x^2 +4) miles by boat, and 6-x miles walking.\nTherefore, the time t is the sum of the distances divided by the rates, or\nt = √(x^2 +4) / 2 + (6-x)/5\n\nTake the derivitive of t with respect to x and set = 0 to find the minimum time.\n\nt = (1/2)(x^2 + 4)^(1/2) - x/5 + 6/5\ndt/dx = (1/2)(1/2)[(x^2+4)^(-1/2)](2x) - 1/5\n= x/[2√(x^2+4)] - 1/5 = 0\n5x = 2√(x^2+4)\n25x^2 = 4x^2 + 16\n21x^2 = 16\nx^2 = 16/21\nx = √(16/21) = 4√21/21 ≈ .87287156 miles from the point on shore nearest the boat.\n\n{Substituting this value back into the equation to find time, we see that the quickest time is ≈2.116515139 hours.}
114675
On land, slower than a tortoise but faster than a rabbit.  In the sea, faster than you and me.
82335
Sound travels at approximately 720 miles per hour. Light travels at 186,000 miles per second.
73649
freestyle, 'cuz u can swim a whole hour w/o tiring much, breaststroke is too slow
425731
hold on to its fin and swim on the side of the dolphin
231622
Swimming is the best. Next is walking in normal speed 5-6 km per hour early morning for 45 minutes to  one hour,daily or at least 5 days in a week..
64737
They are going in same speed, so neither would go faster than the other.
754249
The first car has been traveling for 7.5 hours, so it has covered 330 miles; therefore the second car has been traveling at 330 miles/5.5 hours=60 miles per hour.
669522
It is easiest to think of this in 2 steps.  First, how long does it take the east bound train going 65 mph to travel the 175 miles to the station?\n\nanswer: 175/65=2.6923 hours\n\nStep 2:  How fast does the westbound train need to go to travel the 63 miles in 2.6923 hours?\n\nanswer 63/2.6923 = 23.4 mph
716765
The potential energy at the top is mgR = 2 x10 x R = 20 R.\n\nKinetic energy at the bottom of the curve = 0.5 m U ^2 = 0.5 x 2 x U^2. = U^2.\n\nAs there is no friction  K.E = P.E\n\nU^2 = 20 R.\n\nOn the horizontal path, \n\nInitial speed is U.\n\nFinal speed is V = 0.\n\nDistance traveled = 8 m.\n\nAcceleration = Fricttional Force / mass = -8/ 2 = - 4 m/s^2. ( Negative sign since the force acts opposite to the motion.\n\nUsing V^2 - U^2 = 2as, and also noting that V=0,\n\nU^2 = 2 x 4 x 8 = 64.\n\nU = 8m/s.\n\nThe time of travel is found using V= U+ at.\n\nt = -8/ (-4) = 2 second.\n\nUsing U^2 = 20 R.\n\nR = 64/ 20 = 3.2 m.
530622
Ok, first you want to see where they meet. To make this easier, advance train A for 5/6ths of an hour and see the problem in terms of when train B starts out. 65 x 5/6= 325/6\nkilometers. So the problem is the same only they start out at the same time over a distance of 600- 325/6 kilometer =\n545 5/6 kilometers.\n\nNow, they travel in the proportion of 65/105 kilometers per hour. So the distance till they meet will be in the same proportion. That is 545 5/6 x 65/105 = 212875/630 or about 338 kilometers for train A to travel. Since it travels at 65 kph, this means it travels for 5.2 hours from the new start time equal to B's which was 6:20 AM. Ends up being 11:32AM.
764566
a) 5000*,4 = 2000 feet, so a = 1000 feet\n\nb) x^2/a2 -y2/b^2 =1, where;\n   where the two foci are located at (-c,0) and (c, 0) so c= 4000 ft\n   2a = difference in distances between foci and whale\n   b^2 = c^2-a^2\n\nc) Closest when y = 0 which give x= abs(a)\n\nd) y=+ or - b/a[sqrt ( x^2-a^2)], so if x < a, then y is imaginary. Therefore the region between x=a and x=-a must be excluded, that is, the whale can never be in that region. The whale will always be on the hyperbola branch that is associated with the mike that first receives the signal. The whale can be on either branch of the hyperbola, but never (obviously) on both at the same time. The distance from one foci to the whale will always be < or > than the distance from the other foci to the whale. The distances can never be equal. If they were, this technology would not work.\n\nI believe I included all the info you need to answer the question completely. It would be nice if a diagram could be included.
530417
There are no trains that can travel on water. And the distance betwenn New York and London is much more than 192km. However, if there was such a train....\n1. The speed would be 60km per hour.\n2.It would reach New York at 16:57 London time. I dont know what time that would be in New York.
217138
the particles move faster.
1079489
YOUR LEGS SHOULD STAY TOGETHER AND MOVE IN THE MOTION OF A DOLPHIN. ARMS START OUT IN THE FRONT OF YOU TOGETHER PUSH DOWN WITH HANDS AS YOU ARE MAKING A YOUR ARMS BUTTERFLIED OUT OF WATER OVER HEAD AND PUSH WATER DOWN HEAD COMES EVER OTHER STROKE FOR BREATHE BODY SHOULD HAVE SMOOTH MOVE EVERYTHING WORKS TOGETHER VERY HARD TO DESCRIBE IN WORDS EASIER TO SHOW
537748
Dolphins are most active when the herd is threatened. They will form a defensive line from attackers.