Question 8 - Problems - Chapter 2

Problem:

In 1971, Francis Chichester, in the yacht Gypsy Moth V, attempted to sail the 4000 nautical miles (nmi) from Portuguese Guinea to Nicaragua in no more than 20 days.

Question:

a) What minimumaverage speed (in nmi/h) does it require to mkz the whole trip?

b) After sailing 13 days, he had still 1720 nmi to go. What minimum average speed did he require to reach his goal in the remaining 7 days?

c) Knowing that his yacht could at best achieve a maximum speed of 10 nmo/h, what could he conclude at this point?

Solution:

Total Distance $s = 4000$ nmi

Time = $t = 20$ days$

Average speed $v = \frac{s}{t}$

Distance_tot = 4000 # in nmi
Time_tot = 20 * 24 # in hours
Avg_Speed_tot = Distance_tot / Time_tot
print(f'a) The needed average speed for the total race is {Avg_Speed_tot:.1f} nmi/h.')
Distance_rest = 1720
Time_rest = 7 * 24
Avg_Speed_rest = Distance_rest / Time_rest
print(f'b) The needed average speed to sail the rest-distance within the required time is {Avg_Speed_rest:.1f} nmi/h')
if Avg_Speed_rest <= 10:
    print('c) Yes he can make it within the required time.')
else:
    print('c) No he cannot make it within the required time')

a) The needed average speed for the total race is 8.3 nmi/h.
b) The needed average speed to sail the rest-distance within the required time is 10.2 nmi/h
c) No he cannot make it within the required time