Two towns, P and Q, are on (4oN 40oW) and (4oN
20oE) respectively. What is the distance between
them, along their line of latitude? (Give your
answer in teems of π and R, the radius of the earth).
A
2πR cos4o
B
πR sin40o
C
πR/2 cos4o
D
πR/3 cos4o
E
πR/6 cos4o
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
Angular distance = 40o + 20o = 60o
using θ/360 x 2πr for distance between p and Q
= 60/360 x 2πRcos4o = 1/3πRcos4o
Source: Myschool Past Questions Archive (Record #22918)