senay2008
Answered

Discover the answers to your questions at Westonci.ca, where experts share their knowledge and insights with you. Connect with a community of experts ready to provide precise solutions to your questions on our user-friendly Q&A platform. Explore comprehensive solutions to your questions from a wide range of professionals on our user-friendly platform.

During a school race, Sonic ran around the entire track 5 times in 10 seconds. Everyone was shocked by his speed, which was equal to 321 m/s. FINISH R D In the diagram above, D = 2R. What is the radius of the round part of the track, R, equal to? Use n = 3.14. The answer should be rounded to 3 significant figures.
63.4
62.5
61.4
60.1​

Sagot :

reinhard10158

Step-by-step explanation:

there is no diagram here.

I assume that the race track is a rectangle in the middle and two half-circles at the left and right ends, and that the length of the rectangle is D = 2R. which makes the rectangle actually a square, as the width is the diameter of the (half-)circles, which is also 2R.

Sonic ran the track 5 times in 10 seconds with a speed of 321 m/s.

that means he ran 10×321 m in 10 seconds = 3210 m.

so, 5 times the track is 3210 m, which means that the track itself is 3210/5 = 642 m long.

and based on the assumptions above the track consists of 2 times the length of the rectangle (or square), and the full circumference of a circle with radius R (2 half-circles make one full circle).

we know the formula for the circumference of a circle :

2×pi×radius

so, we have then

642 = 2×2R + 2×pi×R = R×(4 + 2×pi)

R = 642 / (4 + 2×pi) = 62.43201701...

and when using the requested "cut-off" pi = 3.14, we get

R = 642 / (4 + 2×3.14) = 62.45136187...

and that is rounded 62.5

so, the second answer option is correct.

Thanks for using our service. We aim to provide the most accurate answers for all your queries. Visit us again for more insights. We hope this was helpful. Please come back whenever you need more information or answers to your queries. Westonci.ca is here to provide the answers you seek. Return often for more expert solutions.