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Kiley went 5.7 km/h north and then went 5.8 km/h west. From start to finish, she went 8.1 km/h northwest.

User Tachyons
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2 Answers

3 votes

Answer:

the correct answer is D. 5.7 km/h north and 5.8 km/h west are instantaneous velocities, while 8.1 km/h northwest is the average velocity.

Step-by-step explanation:

just took the quiz so that's my explanation

User Felix Ebert
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3 votes

Yes, that's a reasonable rounded value for the solution.

(5.7)² + (5.8)² = (32.49) + (33.64) = 66.13

√66.13 = 8.132...

= 8.1 when rounded to the nearest tenth.

The solution ' 8.1 ' is a reasonable rounded value, but only
if the question is changed to say 'km' at every place where
it now says 'km/hr'.

If 'km/hr' is correct, then there's no way to calculate Kiley's
effective northwesterly speed, using only the given information.

We don't know how long she traveled north at 5.7 km/hr,
and we don't know how long she traveled west at 5.8 km/hr.
So we don't know the distance between her start and end
points, and we don't know how long she traveled altogether ...
exactly the two numbers we need in order to calculate her
average speed. Or even, for that matter, the average direction
of her trip from start to finish.

User Ethel Patrick
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8.8k points