SOLUTION: A woman jogs 4.2 km, 10° E of N and then 2.9 km E at the speed of 8 km/h. How much time would she have saved of she jogged directly to her generation ? In what direction should sh
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Question 1201751: A woman jogs 4.2 km, 10° E of N and then 2.9 km E at the speed of 8 km/h. How much time would she have saved of she jogged directly to her generation ? In what direction should she have headed for this?
Can you also help me draw the vector direction? Only if its okay with you. Thank you Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! A woman jogs 4.2 km, 10° E of N and then 2.9 km E at the speed of 8 km/h. How much time would she have saved of she jogged directly to her generation ?? destination ? In what direction should she have headed for this?
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10° E of N is a heading of 010 degs, an angle of 80 degs with the x-axis.
East is heading of 090, parallel to the x-axis.
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Using Vectors:
Label the points O, A and B in order.
Vector OA is 4.2 km at 080.
The x-component is 4.2*cos(80) = ~0.729 km
The y-comp is 4.2*sin(80) = ~4.14 km
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For AB:
The x-comp is 2.9
The y-comp is 0 (zero).
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Add the x and y comps:
x = 0.729 + 2.9 = 3.629
y = 4.14
---> point B is (3.629,4.14)
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The distance OB = = ~5.5 km
The time difference in hours is 7.1/8 - 5.5/8
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Can you also help me draw the vector direction? Only if its okay with you. Thank you
The "vector directions" are above, 80 degs and 0 degs wrt the x-axis.
The angle of OB wrt the x-axis = atan(y/x) = atan(4.14/3.629) = ~48.8 degs wrt the x-axis ---> a heading of 41.2 degs
