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9 votes
Please help me!!? Number 6

Please help me!!? Number 6-example-1
User Carrier
by
3.4k points

2 Answers

4 votes

Answer: Choice B


\frac{75 \text{ km}}{1 \text{ hr}} * \frac{1000 \text{ m}}{1 \text{ km}} * \frac{1 \text{ hr}}{60 \text{ min}} * \frac{1 \text{ min}}{60 \text{ sec}}

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Step-by-step explanation:

We'll use the following facts (either memorized or written on a reference sheet somewhere)

  • 1000 m = 1 km
  • 1 hr = 60 min
  • 1 min = 60 sec

Each of those equations will form conversion factors to help us go from km/hr to m/s. Each conversion factor is a fraction connecting the two sides of the equation. Example: The equation 1000 m = 1 km forms the conversion factor of
\frac{1000 \text{ m}}{1 \text{ km}}

In choice B, notice how the fractions are set up. The "km" units cancel when dividing. The same goes for the "hr" and "min" units.

Check out the screenshot below where I show this cancellation in action. The color-coding helps show how the terms pair up and cancel.

Choice A comes close to what choice B is saying, but we don't have the "min" units cancel. So choice A is eliminated as an answer.

Choices C and D are also eliminated because of the "75 km" in the denominator. It should be 1 km.

Please help me!!? Number 6-example-1
User Dumisani Kunene
by
3.6k points
7 votes

Answer:

the b believes in me

Step-by-step explanation:

B)75km etc

1hr

User Quuxplusone
by
4.3k points