LSAT－7－1－16

cicilla

16. Comets do not give off their own light but reflect light from other sources, such as the Sun. Scientists estimate the mass of comets by their brightness by their brightness: the greater a comet’s mass, the more light that comet will reflect. A satellite probe, however, has revealed that the material of which Halley’s comet is composed reflects 60 times less light per unit of mass than had been previously thought.

The statements above, if true, give the most support to which one of the following?

(A) Some comets are composed of material that reflects 60 times more light per unit of mass than the material of which Halley’s comet is composed.

(B) Previous estimates of the mass of Halley’s comet which were base on its brightness were too low.

(C) The total amount of light reflected from Halley’s comet is less than scientists had previously thought.

(D) The reflective properties of the material of which comets are composed vary considerably from comet to comet.

(E) Scientists need more information before they can make a good estimate of the mass of Halley’s comet.

The Key is B, Why B? I chose C. 是不是最后一句话我理解反了？谢谢！

robertchu

It's already known (observed) how much light the Halley's Comet reflects.  So, C is obviously wrong.

Since Halley is less reflective than previously thought, so it's actually mass is much higher than originally thought.  Therefore B is the best answer.

huar

不好意思,楼上的好象没有说清楚啊,因为文章不是说:
MASS 越大,LIGHT越多?

lawyer_1

单位质量反射的光（A）=反射的光（B）/质量（C）。原文说A实际值比估计值低，则C实际值比估计值高（因为反射的光没错）。即原来的估计太低啦。其实考试时不必这麽复杂，排除法就行。

hedonism555

originally,   1 mass =>  70 light

actually,     1 mass => 10 light

the ratio is transformed from 1 : 70 to 1 : 10.  So, if the constant number of light stays the same, then the constant number of mass must increase to compensate the shrunk ratio.

questionmark

恩，这道题我也是没有看清最后一句话还有个per unit的概念。谢谢几为NN

xjlv128

我也是被最后一句话绕进去的

ypngzhang

以下是引用lawyer_1在2005-1-27 22:49:00的发言：
单位质量反射的光（A）=反射的光（B）/质量（C）。原文说A实际值比估计值低，则C实际值比估计值高（因为反射的光没错）。即原来的估计太低啦。其实考试时不必这麽复杂，排除法就行。

为什么反射的光是个常数？原文不是说 greater a comet’s mass, the more light that comet will reflect

请NN指教。多谢！！

ssssss

6. Comets do not give off their own light but reflect light from other sources, such as the Sun. Scientists estimate the mass of comets by their brightness: the greater a comet’s mass, the more light that comet will reflect. A satellite probe, however, has revealed that the material of which Halley’s comet is composed reflects 60 times less light per unit of mass than had been previously thought.

The statements above, if true, give the most support to which one of the following?

This is a generalization type of question:

(A) Some comets are composed of material that reflects 60 times more light per unit of mass than the material of which Halley’s comet is composed.

Cannot infer this from the question
                

(B) Previous estimates of the mass of Halley’s comet which were base on its brightness were too low.

This can be infer from it, since Halley’s comet is composed reflects 60 times less light per unit of mass than had been previously thought, so the actually weight of halley’s comet is much heavier.

(C) The total amount of light reflected from Halley’s comet is less than scientists had previously thought.

Can not infer this for it, it did not mention about the amount of light reflected at all.

(D) The reflective properties of the material of which comets are composed vary considerably from comet to comet.

Out of scope

(E) Scientists need more information before they can make a good estimate of the mass of Halley’s comet.

Out of scope

zxzhyzcy