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Your lab experiments showed that -rays ( is the greek letter gamma) are stopped

ID: 160078 • Letter: Y

Question

Your lab experiments showed that -rays ( is the greek letter gamma) are stopped by a dense material such as lead. The Sun's inner core is on average 10 times denser than lead (though not composed of lead) and the absorbed gamma rays are re-emitted. (Note that the Sun's diameter is 1.4 x 10^6 km).

(a) If a -ray is stopped by 2 cm of lead in the laboratory, then about how far will it travel in the Sun's interior before it gets absorbed?

The answer is 0.2 cm but I do not know why?

(b)The Sun's inner core extends from the center out to about 25% of its full radius. About how many times will a -ray be absorbed and re-emitted before it reaches the edge of the core if it travels in a straight line?

The answer is 9 x 10^10 but I do not know why?

(c)If the speed of light is 3x10^5 km/sec and a -ray takes 10^5 years to exit the core of the Sun: how many times faster is the speed of light compared to the average outward velocity of a -ray?

The answer is 5.5 x 10^12 but I do not know why?

Explanation / Answer

Your lab experiments showed that -rays ( is the greek letter gamma) are stopped