Quick math question involving trig.?

Question

A camel sets out to cross the desert, which

is 41.3 km wide in the north-south direction. The camel walks at the uniform speed 3.71 km/hr along a straight line in the direction 41.8(degrees) north of East. How many hours will it take the camel to cross the

desert? - i got 229.88 hours but me and my partner don't agree.

Whats the camel’s eastward displacement

while he crosses the desert? - no clue?

Anybody? please =]

Answer 1

A camel sets out to cross the desert, which

is 41.3 km wide in the north-south direction. The camel walks at the uniform speed 3.71 km/hr along a straight line in the direction 41.8(degrees) north of East. How many hours will it take the camel to cross the

desert? - i got 229.88 hours but me and my partner don't agree.

Bibi here it is

http://www.flickr.com/photos/27678773@N0...

Width NS direction = 41.3 km

Angle of inclination = 41.8°

Speed of camel = 3.71 km/hr

The camel has to travel NS/Cos 41.8° to equal the distance of 41.3 km

The camel has to travel = 41.3/Cos 41.8

The camel has to travel = 41.3 / 0.745

The camel has to travel = 55.44 km

The camel reach the destination at = 55.44 / camel Speed

The camel reach the destination at = 55.44 / 3.71

======================================...

Ans:: The camel reach the destination at = 14.92 hours

======================================...

hope this helps

Answer 2

41.8º = 41.8π/180 radians = 0.2322π radians

Cos(π/2 - 0.2322π) = 41.3/distance

distance = 61.96 km

rate x time = distance

time = distance/rate

61.96 km/3.71 kph = 16.7 hrs

Tan(π/2 - 0.2322π) = (eastward displacement)/(north-south length)

Tan(π/2 - 0.2322π) = (eastward displacement)/41.3

eastward displacement = 46.2 km

Answers: 16.7 hrs, 46.2 km

Answer 3

You are on the right track--I'm guessing you found a distance of 61.9625 km.  Recheck your distance=rate*time:  61.9625=3.71*time.

As for eastward displacement, you've got hyp = 61.9625, and you want to find the length of the side adjacent to your angle.

cos 41.8 = side adj/hypotenuse    Solve for side adjacent.

When in doubt, draw a picture, because like my math teacher used to say, "A picture is worth a thousand words."