Two submarines, one cruising at 25 knots and the other at 20 knots, left a naval base at the same moment. Three hours later, they were 100 nautical miles apart. What was the measure of the angle between their courses?

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agaue agaue · Answer 1 · 2019-12-25T06:59:59+01:00

Step-by-step explanation:

Speed of submarine 1 = 25 knots = 28.77 mph

Speed of submarine 2 = 20 knots = 23 mph

Time taken = 3 hours

Distance traveled by submarine 1 = 28.77 x 3 = 86.31 miles

Distance traveled by submarine 2 = 23 x 3 = 69 miles

Distance between them is 100 nautical miles = 115.08 miles

Refer the figure

By cosine formula we have

[tex]cosB=\frac{a^2+c^2-b^2}{2ac}[/tex]

a = 86.31 miles

b = 115.08 miles

c = 69 miles

Substituting

[tex]cosB=\frac{86.31^2+69^2-115.08^2}{2\times 86.31\times 69}\\\\cosB=-0.0867\\\\B=94.98^0=95^0[/tex]

Measure of the angle between their courses is 95°

kunyuanchu kunyuanchu · Answer 2 · 2020-11-17T05:33:39+01:00

Answer:

The correct answer is 95°

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