Context and question: The term mainly refers to a mix of lithium and aluminosilicates that yields an array of materials with interesting thermomechanical properties. The most commercially important of these have the distinction of being impervious to thermal shock. Thus, glass-ceramics have become extremely useful for countertop cooking. The negative thermal expansion coefficient (CTE) of the crystalline ceramic phase can be balanced with the positive CTE of the glassy phase. At a certain point (~70% crystalline) the glass-ceramic has a net CTE near zero. This type of glass-ceramic exhibits excellent mechanical properties and can sustain repeated and quick temperature changes up to 1000 C.
What ingredients give glass-ceramics its useful heat tolerance?
Answer: lithium and aluminosilicates
Context and question: In recent years the city government, under Mayor Manny Diaz, has taken an ambitious stance in support of bicycling in Miami for both recreation and commuting. Every month, the city hosts "Bike Miami", where major streets in Downtown and Brickell are closed to automobiles, but left open for pedestrians and bicyclists. The event began in November 2008, and has doubled in popularity from 1,500 participants to about 3,000 in the October 2009 Bike Miami. This is the longest-running such event in the US. In October 2009, the city also approved an extensive 20-year plan for bike routes and paths around the city. The city has begun construction of bike routes as of late 2009, and ordinances requiring bike parking in all future construction in the city became mandatory as of October 2009.
How many people participated in Bike Miami in October of 2008?
Answer: unanswerable
Context and question: A higher flight phase results in a higher vertical ground reaction force. Vertical ground reaction force represents external force which the gymnasts have to overcome with their muscle force and has an impact on the gymnasts linear and angular momentum. Another important variable that affects linear and angular momentum is time the landing takes Gymnasts can alter the shape of the area by increasing the time taken to perform the landing. Gymnasts can achieve this by increasing hip, knee and ankle amplitude. With the increase of height, the amplitude in ankles knees and hips rise the bars.
What happens when gymnasts decrease the time taken to perform the landing?
Answer:
unanswerable