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A river has a current of 4 mph find the speed of simons boat in still water if it goes 40 miles downstream in the same time as 24 miles upstream?
Wiki User
∙ 14y ago
Let s = unknown speed in still water in units of miles per hour. The downstream speed will then be s + 4 and the upstream speed s - 4. In an equal time t in units of hours, t(s+4) = 40 and t(s-4) = 24. Multiplying out the parenthetical expressions yields ts + 4t = 40 and ts - 4t = 24. Subtracting the second of these equations from the first gives 8t = 16, or t = 2 hours. Therefore, ts +4t = 40, by substituting 2 for t becomes:
2s + 8 = 40, or 2s = 40 - 8 = 32, or s = 16 miles per hour.
Wiki User
∙ 14y ago
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If Tina swims 4 miles upstream at 1 mph and back downstream to the same point at 4 miles per hour what is her average speed?
2 Miles An Hour.
A motorboat maintained a constant speed of 24 miles per hour relative to the water going 35 miles upstream and then returning the total time for the trip was 3.0 hours What is the speed of current?
The current speed is about 4 miles per hour.
If a boat can go 20 miles per hours in still water and can go six miles downstream and 3 miles up stream in the same time how fast is the river?
assume river velocity = X mph boat velocity = 20 mph time to go 6 miles downstream = T1 time to go 3 miles upstream = T2 distance = time * velocity downstream: 6 mi = T1 * (boat velocity + river velocity) upstream: 3 mi = T2 * (boat velocity - river velocity) 6 = T1 * ( 20 + X ) 3 = T2 * ( 20 - X ) T1 * ( 20 + X ) = 2 * ( T2 * ( 20 - X ) ) since T1 = T2 then 20 + X = 40 - 2X 3X = 20 X = 6.67 thus, river velocity is 6.67mph
Julie and Eric row their boat at a constant speed 40 miles downstream for 4 hours helped by the current?
The average speed downstream is 40 ÷ 4 = 10 mph. However, it would seem that insufficient information has been supplied to enable a satisfactory answer to this question to be provided.
If a river current is 8.0 miles per second and a boat is traveling 10.0 miles per second upstream what is the boat's speed relative to the riverbank?
2 miles per second upstream relative to the river bank.Note: This is quite a scenario, even for experienced rapids-shooters.That river is flowing at 28,800 miles per hour, and the guy is paddlinghis kayak through the water at 36,000 miles per hour. The whole sceneis definitely poised to launch itself into solar orbit.
If a motorboat can go 8 miles downstream on a river in 20 mins if the return 8 miles upstream takes 30 minutes what is the speed of the current?
The current is approximately 4 mph.
If Tina swims 4 miles upstream at 1 mph and back downstream to the same point at 4 miles per hour what is her average speed?
2 Miles An Hour.
A motor boat can go 2 miles downstream on a river in 3 minutes it takes 15 minutes for the boat to go upstream the same 2 miles find the speed of the current?
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
A boat on the Missouri river took 2 hours to go 48 miles downstream. The boat took 3 hours to return the same distance upstream. Find the rate of the boat in still water and the rate of the current.?
Boats speed = 24 miles per hour.Current speed = 4 miles per hour.
What is the gradient of the river amzon?
The gradient of the River Amazon is very low. It is 1,000 miles or 1,610 kilometers upstream, and 100 feet or 30 meters downstream.
If Tina swims 4 miles upstream at 1 mph and back downstream to the same point to the same point at 4 mph what is her average speed?
8 MPH
A man rows upstream for 20 miles in 5 hours and 10 miles downstream in 2 hrs What is the speed of the man in still water?
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
If Tina swims 4 miles upstream at 1 mph and back downstream to the same point at 4 mph what is her average speed?
Her average speed is 1.6 miles per hour. Average speed is total distance covered by total time taken to do it. She swims 4 miles upstream, and at 1 mph, it takes 4 hours. She comes back downstream at 4 mph and so she covers the 4 miles in 1 hour. Her total mileage is 8 miles. It takes 4 + 1 hours or 5 hours to cover it. The 8 miles divided by 5 hours is 1 3/5 miles per hour, or 1.6 mph for an average speed.
A motorboat maintained a constant speed of 24 miles per hour relative to the water going 35 miles upstream and then returning the total time for the trip was 3.0 hours What is the speed of current?
The current speed is about 4 miles per hour.
It takes a motor boat 3 hours to make a downstream trip with a current of 7 miles per hour the return trip against the same current took 5 hours find the speed of the boat in still water?
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.
If a boat can go 20 miles per hours in still water and can go six miles downstream and 3 miles up stream in the same time how fast is the river?
assume river velocity = X mph boat velocity = 20 mph time to go 6 miles downstream = T1 time to go 3 miles upstream = T2 distance = time * velocity downstream: 6 mi = T1 * (boat velocity + river velocity) upstream: 3 mi = T2 * (boat velocity - river velocity) 6 = T1 * ( 20 + X ) 3 = T2 * ( 20 - X ) T1 * ( 20 + X ) = 2 * ( T2 * ( 20 - X ) ) since T1 = T2 then 20 + X = 40 - 2X 3X = 20 X = 6.67 thus, river velocity is 6.67mph
A boat makes a 120-mile trip downstream in 3 hours but makes the return trip in 4 hours. What is the rate of the current?
It is 5 miles per hour.
