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 Boats and Streams 32 Flashcards |
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The formula for the speed of a boat in still water is calculated using the downstream and upstream speeds. Fill in the blank: Speed of boat in still water = (___ + ___) / 2. |
Card: 1 / 32 |
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Downstream speed + Upstream speed |
Card: 2 / 32 |
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True or False: If a boat's downstream speed is greater than its upstream speed, this indicates that the stream is flowing downstream. |
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True |
Card: 4 / 32 |
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Calculate the speed of the stream if a boat can row downstream at 10 km/h and upstream at 6 km/h. |
Card: 5 / 32 |
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Speed of stream = (10 - 6) / 2 = 2 km/h |
Card: 6 / 32 |
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A boat travels 40 km downstream in 2 hours. What is the downstream speed? |
Card: 7 / 32 |
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Downstream speed = 40 / 2 = 20 km/h |
Card: 8 / 32 |
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What is the time taken for a boat to cover 60 km upstream at a speed of 6 km/h if the stream speed is 2 km/h? |
Card: 9 / 32 |
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Effective upstream speed = 6 - 2 = 4 km/h; Time = 60 / 4 = 15 hours |
Card: 10 / 32 |
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A man can row 15 km/h in still water. If the stream flows at 5 km/h, what is his effective speed downstream? |
Card: 11 / 32 |
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Effective downstream speed = 15 + 5 = 20 km/h |
Card: 12 / 32 |
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Fill in the blank: A boat's speed upstream is always ___ than its speed downstream due to the opposing current. |
Card: 13 / 32 |
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Less |
Card: 14 / 32 |
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A boat covers 30 km downstream in 1.5 hours. Determine its downstream speed. |
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Downstream speed = 30 / 1.5 = 20 km/h |
Card: 16 / 32 |
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True or False: If a boat takes longer to travel upstream than downstream for the same distance, it indicates that the stream is very strong. |
Card: 17 / 32 |
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True |
Card: 18 / 32 |
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What is the ratio of the speed of the boat in still water to the speed of the stream if the boat rows downstream at 18 km/h and upstream at 12 km/h? |
Card: 19 / 32 |
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Let speed of stream = x; 18 = (speed of boat + x) and 12 = (speed of boat - x); Solve to find ratio. |
Card: 20 / 32 |
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Fill in the blank: The speed of the stream can be calculated using the formula: Speed of stream = (___ - ___) / 2. |
Card: 21 / 32 |
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Downstream speed - Upstream speed |
Card: 22 / 32 |
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Calculate the time it will take for a boat traveling 50 km downstream at 15 km/h to return upstream against a current if the stream speed is 5 km/h. |
Card: 23 / 32 |
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Time downstream = 50 / 15 = 3.33 hours; Effective upstream speed = 15 - 5 = 10 km/h; Time upstream = 50 / 10 = 5 hours. |
Card: 24 / 32 |
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True or False: The speed of a boat is the same whether it is traveling upstream or downstream. |
Card: 25 / 32 |
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False: The speed differs due to the effect of the stream. |
Card: 26 / 32 |
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A man can swim at 7 km/h in still water. If the river flows at 3 km/h, how long will he take to swim 21 km upstream? |
Card: 27 / 32 |
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Upstream speed = 7 - 3 = 4 km/h; Time = 21 / 4 = 5.25 hours. |
Card: 28 / 32 |
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Fill in the blank: The total time taken for a boat to return upstream can be calculated by the formula: Time upstream = Distance / (Speed in still water - ___). |
Card: 29 / 32 |
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Stream speed |
Card: 30 / 32 |
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The formula for the speed of a boat in still water is calculated as ___ if the downstream and upstream speeds are known. |
Card: 31 / 32 |
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Speed of boat in still water = (Downstream speed + Upstream speed) / 2 |
Card: 32 / 32 |
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