A river is flowing at the rate of 2.4 miles an hour when a boy rows across it. If the boy rows at a still-water speed of 3.1 mil
es per hour and heads the boat perpendicular to the direction of the current. The ground speed of the boat is _____ miles per hour.
1 answer:
Answer:
3.9 mi/h
Step-by-step explanation:
If the boy is rowing perpendicular to the current, the two vectors form a right triangle.
AB represents the downstream current, BC is the speed across the river, and AC is the ground speed of the boat
AC^2 = 2.4^2 + 3.1^2 =5.76 + 9.61 = 15.37
AC = sqrt(15.37) = 3.9 mi/h
The boat's speed over the ground is 3.9 mi/h.
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Answer:
Option C is correct.
Step-by-step explanation:
Points given are
(1,2) and (3,8)
The formula used for slope is:
x₁ = 1, x₂=3, y₁=2 and y₂=8
So, slope =3
Option C is correct.