LSAT 143 | Section 2 | Reading Comprehension: Q27

RC Question 27 Explanation

QUESTION TEXT: The passage suggests that which one of the…

DISCUSSION: The transition temperature is mentioned in two places:

• Lines 13-17: The transition temperature is a few hundred degrees celsius.
• Lines 41-43: Glass would need to be heated to at least 350 degrees to flow more rapidly.

So the passage doesn’t define transition temperature in precise detail. But the “at least 350 degrees” implies that the hotter glass is, the faster it flows. And the 350 degrees is the bare minimum for glass to start flowing at a noticeable rate.

___________

1. You might have picked this because you remembered that impurities in medieval glass make it flow more quickly (lines 35-36). There are two problems with this:

   • These impurities may only affect viscosity/flow speed, not transition temperature itself.
   • The impurities increase flow speed. So if anything, they lower transition temperature. This answer says they raise transition temperature.
2. This answer defies common sense. People have been working with and melting glass for thousands of years. It would be insane to believe that glassworkers didn’t know the transition temperature of glass.
   If an answer seems insane in the real world, it’s probably not the right answer. You need extremely clear justification from the passage to pick an answer like this.
3. CORRECT. See the discussion section above. 350 degrees is the bare minimum for glass to start flowing. So the upper extreme of the transition temperature must be much higher.
4. This contradicts the passage. Once glass passes the transition temperature, it begins to flow (lines 41-43). Glass can even become liquid and float (see line 56).
5. This isn’t supported. Lines 41-43 appear to be saying that all glass must be heated above 350 degrees celsius to flow even a little.