Let the velocity in still water be V and the current be U. The net velocity upstream (against the current) is 20/6 = V - U . The net velocity downstream is ,18/4 = V + U. Add the equations to get 7.83 = 2V . Subtract the equations to get, 1.17 = 2U. So, V= 3.91 and U = .58
The boat would make no progress.
Velocity = Distance ÷ Time.The speed upstream = 300 ÷ 5 = 60kph.The speed downstream = 300 ÷ 2 = 150 kph.The speed upstream equals boat velocity(Vb) minus current velocity(Vc).The speed downstream equals boat velocity (Vb) pluscurrent velocity (Vc).Vb - Vc = 60Vb + Vc = 150 : Adding the two equations together gives :-2Vb = 210 : Vb = 105, therefore Vc = 45The rate of the boat in still water is 105 kph. The rate of the current is 45 kph.
adsl
The current is approximately 4 mph.
Incoming rate or speed. As in download as opposed to upload or upstream.
Call the unknown speed of the current c and the speed of the boat in still water b. When travelling upstream, the net speed of the boat will be b - c and when travelling downstream the net speed of the boat will be b + c. Since b = 4c, the speed upstream will be 3c. The distance upstream is one-half the total travelling distance of 150 km or 75 kilometers. Distance travelled = speed X time at speed, so that upstream time = 75/3c, downstream time = 75/5c, and the sum of these is the total time stated to be 8 hours. Thus 75/3c + 75/5c = 8. Multiplying both sides by 15c yields 75(5 +3) = 120c, or c = (8 X 75)/120 = 5 kilometers per hour.
The speed upstream is B - C where B is the speed of the badge in still water and C is speed of the current The speed downstream is B + C. Velocity = Distance/Time : therefore Time = Distance/Velocity. Time for upstream journey = 6/(B - C) Time for downstream journey = 6/(B + C) BUT Total time for journey = 2 = 6/(B - C) + 6/(B + C) = 12B/(B2 - C2) Therefore 2B2 - 2C2 = 12B : However, B = 8kph so substituting gives, 128 - 2C2 = 96 : 2C2 = 32 : C2 = 16 : C = 4 The speed of the current is 4kph.
ADSL is simply a version or 'flavour' of DSL. The 'a' refers to asymmetric, meaning 'not the same'. Hence, ADSL usually has different downstream and upstream rates (e.g. 1536/256 is a common speed of ADSL available in Australia, where downstream the link speed is 1536kbps and upstream is 256kbps).
2.2 Type your answer here...
Let boat speed = X and current speed = Y Downstream speed = boat speed plus current speed = X + Y Upstream speed = boat speed minus current speed = X -Y Downstream speed = 2 miles divided by 3 minutes = 2/3 miles per minute Upstream speed = 2 miles divided by 15 minutes = 2/15 miles per minute X + Y = 2/3 X - Y = 2/15 add equations 2X = 2/3 + 2/15 = 10/15 + 2/15 = 12/15 = 4/5 divide by 2 X = 4/10 = 2/5 use second equation and find Y as X -Y = 2/15 2/5 - Y = 2/15 6/15 - Y = 2/15 Y = 4/15 = current speed = 0.266 miles per minute
Since the distance downstream (with the current) equals the distance upstream (against the current), and if we: Let B stand for the speed (rate in mph) of the boat in still water, and using the formula rate X time = distance, the equation will be: (B+7) x 3 = (B-7) x 5 3B + 21 = 5B - 35 56 = 2B B = 28 mph Traveling downstream, the current will cause the boat to go faster so the 7 mph current is added to the boat's still water speed. Traveling upsteam the current slows or decreases the boat's rate so the current's speed is subtracted from the boat's still water speed.
Speed upstream(S.u) = 20/5 => 4miles/hr Speed downstream(S.d) = 10/2 => 5miles/hr Speed of man in still water(speed of boat in still water)= 1/2 * (S.u + S.d) = 0.5 * (4 + 5) = 0.5 *9 = 4.5miles/hr The speed of man in still water is 4.5 miles/hr