To find the time Jack takes to cross Swan Lake, his average speed is required:
The time it will take Jack to cross Swam Lake is <u>0.5 hours</u>
Reason:
Time it took Jack to paddle 6.4 km upstream, t = 2 hours
Distance Jack paddled, d = 6.4 km
The given speed of the Black River, <em>v₂</em> = 1.8 km/h
The width of the lake, w = 2.5 km
The time it will take Jack to cross Swan Lake
Let <em>v₁</em>, represents Jack's speed, we have;
Therefore;
v₁ = 3.2 + 1.8 = 5
- Jack's speed, v₁ = 5 km/h
The time it will take Jack to cross Swan Lake, = <u>0.5 hours</u>
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