43. A commonly used unit of mass in the English system is the pound-mass, abbreviated lbm, where 1 lbm =

0.454 kg. What is the density of water in pound-mass per cubic foot?

27. Suppose you walk 18.0 m straight west and then 25.0 m straight north. How far are you from your starting

point and what is the compass direction of a line connecting your starting point to your final position? Use a

graphical method.

31. In an attempt to escape a desert island, a castaway builds a raft and sets out to sea. The wind shifts a

great deal during the day and he is blown along the following directions: 2.50 km and 45.0° north of west, then

4.70 km and 60.0° south of east, then 1.30 km and 25.0° south of west, then 5.10 km straight east, then 1.70

km and 5.00° east of north, then 7.20 km and 55.0° south of west, and finally 2.80 km and 10.0° north of

east. Use a graphical method to find the castaway's final position relative to the island.

36. The magnitudes of two displacement vectors are A = 20 m and B = 6 m. What are the largest and the

smallest values of the magnitude of the resultant R = A + B?

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75. Starting at the island of Moi in an unknown archipelago, a fishing boat makes a round trip with two stops at

the islands of Noi and Poi. It sails from Moi for 4.76 nautical miles (nmi) in a direction 37° north of east to Noi.

From Noi, it sails 69° west of north to Poi. On its return leg from Poi, it sails 28° east of south. What distance

does the boat sail between Noi and Poi? What distance does it sail between Moi and Poi? Express your

answer both in nautical miles and in kilometers. Note: 1 nmi = 1852 m.