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Kenna and Sariah are in an outdoor education camp in Waterton National Park, one of the...
Kenna and Sariah are in an outdoor education camp in Waterton National Park, one of the activities is the orientation. Kenna's instructions are to walk to a direction of N20 ° W. Her average speed of walking on uneven ground is 3.5 km / h. Sariah's instructions are to walk to a direction of N33 ° E. The average walking speed is 1.0 km / h faster than Kenna because her career is covered in flat terrain towards a lake. How far will the girls be after 20 minutes of walk?
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N20 ° W would be 20 degrees past N on the way to W. Similarly N33 ° E would be 20 degrees past N on the way to E.
Let they starts together at the same time from point P.
Kenna travels towards N20 ° W at 3.5 km / h. Sariah travels towards N20 ° E at 4.5 km / h.
After 20 minutes, Kenna is at K, which is 3.5*20/60 = 1.1667 km away from P.
Similarly, after 20 minutes, Sariah should reach at S, which is 4.5*20/60 = 1.5 km away from P.
From the triangle PKS, side KS can be obtained from the cosine formula of triangles:
Therefore, after 20 minutes Kenna and Sariah will be 1.227 kM apart.
Posted by llltkl on July 8, 2013 at 3:24 PM (Answer #1)
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