Two persons are to run a race, but one can run 10 meters per second, whereas the other can run 4 meters per second. If the slowe
2 answers:
Answer:
12.5 seconds
Step-by-step explanation:
Speed of the first person = 10 meter per second
Speed of the second person = 4 meter per second
Relative velocity of faster person = 10 - 4 = 6 meter per second
since distance between both the person is = 75 meter.
Therefore, time to cover this distance by faster person =
= 12.5 seconds.
Faster runner catches the slower runner after 12.5 seconds.
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Since a calculator is involved in finding the answer, it makes sense to me to use a calculator capable of adding vectors.
The airplane's ground speed is 158 mph, and its heading is 205.3°.
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A diagram can be helpful. You have enough information to determine two sides of a triangle and the angle between them. This makes using the Law of Cosines feasible for determining the resultant (r) of adding the two vectors.
.. r^2 = 165^2 +15^2 -2*165*15*cos(60°) = 24975
.. r = √24975 ≈ 158.03
Then the angle β between the plane's heading and its actual direction can be found from the Law of Sines
.. β = arcsin(15/158.03*sin(60°)) = 4.7°
Thus the actual direction of the airplane is 210° -4.7° = 205.3°.
The ground speed and course of the plane are 158 mph @ 205.3°.
The airplane's ground speed is 158 mph, and its heading is 205.3°.
_____
A diagram can be helpful. You have enough information to determine two sides of a triangle and the angle between them. This makes using the Law of Cosines feasible for determining the resultant (r) of adding the two vectors.
.. r^2 = 165^2 +15^2 -2*165*15*cos(60°) = 24975
.. r = √24975 ≈ 158.03
Then the angle β between the plane's heading and its actual direction can be found from the Law of Sines
.. β = arcsin(15/158.03*sin(60°)) = 4.7°
Thus the actual direction of the airplane is 210° -4.7° = 205.3°.
The ground speed and course of the plane are 158 mph @ 205.3°.