A ship sets sail from port A (86\(^o\)N, 56\(^o\)W) for port B (86\(^o\)N, 64\(^o\)W), which is close by. Find the distance the ship covered from port A to port B, correct to the nearest km.

[Take \(\pi\) = 3.142 and R = 6370 km]

A.

62 km

B.

97 km

C.

389 km

D.

931 km

Correct answer is A

AB = \(\frac{θ}{360}\times 2\pi Rcos\propto\) (distance on small circle)

= 64 - 56 = 8\(^o\)

\(\propto = 86^o\)

⇒ AB = \(\frac{8}{360}\) x 2 x 3.142 x 6370 x cos 86

⇒ AB = \(\frac{22,338.29974}{360}\)

∴ AB = 62km (to the nearest km)