Homework Help

Kenna and Sariah are in an outdoor education camp in Waterton National Park, one of the...

user profile pic

babylove12 | Student, Grade 10 | (Level 3) eNoter

Posted July 8, 2013 at 2:40 PM via web

dislike 1 like

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?

1 Answer | Add Yours

user profile pic

llltkl | College Teacher | (Level 3) Valedictorian

Posted July 8, 2013 at 3:24 PM (Answer #1)

dislike 1 like

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:

`c=sqrt(PK^2+PS^2-2PK*PScos53)`

`=sqrt((1.1667)^2+(1.5)^2-2*1.1667*1.5*0.6018)`

`=sqrt(1.5048)`

`=1.227 kM` 

Therefore, after 20 minutes Kenna and Sariah will be 1.227 kM apart.

Images:
This image has been Flagged as inappropriate Click to unflag
Image (1 of 1)

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes