PT137.S3.Q10

PrepTest 137 - Section 3 - Question 10

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A ring of gas emitting X-rays flickering 450 times per second has been observed in a stable orbit around a black hole. ██ █████ ██ ███████ ██████ ████████ ████████ █████████ ████ ████ ██ ██████████ ███ ████ ██ █████████ ██ ███ ████ ██ ███ ███ █ ██████ ██ ██ ███████████ ███ ███ ███ ████ █████ ███ ████████ ██ █████ ██ █████ ██ █ █████ ████ ██████ ███ █████ ████ ███ █████████

Summary

Scientists have seen a ring of gas that maintains a stable orbit around a black hole. The gas ring emits X-rays that flicker 450 times per second. This flickering speed suggests that the gas ring has a radius of 49 kilometers, meaning that it is very close to the black hole. However, for the gas ring to maintain its orbit so close to the black hole, the black hole itself must be spinning.

Strongly Supported Conclusions

In some conditions, gas can orbit black holes at a close distance.

The black hole is spinning.

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10.

The statements above, if true, ████ ████████ ███████ █████ ███ ██ ███ ██████████ ████████ ████ ███ ██████ ████████ ████████ ████████ ████████ ██ █████ ███ ████████

a

Black holes that ████ ████████ █████ ██ ███ ████ █████ ███████ ████ ██ ██████████ ███ ███████ ███████████

b

Only rings of ███ ████ ███ ██ ██████ ██████ ██████ █████ █████ ████ ██████████ ███████

c

The black hole ████ ██ ██████ ███ ████ ██ ███ ████████ ██ ███ ███████████ ██ █████████

d

X-rays emitted by █████ ██ ███ ████████ █████ █████ █████ █████ █████ █████ ██ █████

e

A black hole ██ ██████████ ████ ██ ██ ██ ███████ ██ █ ████ ██ ███ ████ █ ██████ ██ ████ ████ ██ ███████████

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