instruction:
Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.
question:
Context: Richard Packard is an American physicist, a professor at the University of California, Berkeley, known for having built the first quantum gyroscope with his colleagues. 
 Question: What is Richard Packard's place of employment?
answer:
university of california, berkeley


question:
Context: Assume that a school bus, like the one in Figure 12.2, passes by as you stand on the sidewalk. Its obvious to you that the bus is moving. It is moving relative to you and the trees across the street. But what about to the children inside the bus? They arent moving relative to each other. If they look only at the other children sitting near them, they will not appear to be moving. They may only be able to tell that the bus is moving by looking out the window and seeing you and the trees whizzing by. This example shows that how we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion. For the children on the bus, if they use other children riding the bus as their frame of reference, they do not appear to be moving. But if they use objects outside the bus as their frame of reference, they can tell they are moving. What is your frame of reference if you are standing on the sidewalk and see the bus go by? How can you tell the bus is moving? The video at the URL below illustrates other examples of how frame of reference is related to motion. MEDIA Click image to the left or use the URL below. URL: Did you ever go to a track meet like the one pictured in Figure 12.3? Running events in track include 100-meter sprints and 2000-meter races. Races are named for their distance. Distance is the length of the route between two points. The length of the route in a race is the distance between the starting and finishing lines. In a 100-meter sprint, for example, the distance is 100 meters. The SI unit for distance is the meter (1 m = 3.28 ft). Short distances may be measured in centimeters (1 cm = 0.01 m). Long distances may be measured in kilometers (1 km = 1000 m). For example, you might measure the distance a frogs tongue moves in centimeters and the distance a cheetah moves in kilometers. Maps can often be used to measure distance. Look at the map in Figure 12.4. Find Mias house and the school. You can use the map key to directly measure the distance between these two points. The distance is 2 kilometers. Measure it yourself to see if you agree. Things dont always move in straight lines like the route from Mias house to the school. Sometimes they change direction as they move. For example, the route from Mias house to the post office changes from west to north at the school (see Figure 12.4). To find the total distance of a route that changes direction, you must add up the distances traveled in each direction. From Mias house to the school, for example, the distance is 2 kilometers. From the school to the post office, the distance is 1 kilometer. Therefore, the total distance from Mias house to the post office is 3 kilometers. You Try It! Problem: What is the distance from the post office to the park in Figure 12.4? Direction is just as important as distance in describing motion. For example, if Mia told a friend how to reach the post office from her house, she couldnt just say, "go 3 kilometers." The friend might end up at the park instead of the post office. Mia would have to be more specific. She could say, "go west for 2 kilometers and then go north for 1 kilometer." When both distance and direction are considered, motion is a vector. A vector is a quantity that includes both size and direction. A vector is represented by an arrow. The length of the arrow represents distance. The way the arrow points shows direction. The red arrows in Figure 12.4 are vectors for Mias route to the school and post office. If you want to learn more about vectors, watch the videos at these URLs: (5:27) MEDIA Click image to the left or use the URL below. URL: You Try It! Problem: Draw vectors to 
 Question: When both distance and direction are considered, motion
answer:
is a vector.


question:
Context: With more greenhouse gases trapping heat, average annual global temperatures are rising. This is known as global warming. While temperatures have risen since the end of the Pleistocene, 10,000 years ago, this rate of increase has been more rapid in the past century, and has risen even faster since 1990. The 10 warmest years in the 134-year record have all occurred since in the 21st century, and only one year during the 20th century (1998) was warmer than 2013, the 4th warmest year on record (through 2013) (Figure 1.1). The 2000s were the warmest decade yet. Annual variations aside, the average global temperature increased about 0.8o C (1.5o F) between 1880 and 2010, according to the Goddard Institute for Space Studies, NOAA. This number doesnt seem very large. Why is it important? The United States has long been the largest emitter of greenhouse gases, with about 20% of total emissions in 2004. As a result of Chinas rapid economic growth, its emissions surpassed those of the United States in 2008. However, its also important to keep in mind that the United States has only about one-fifth the population of China. Whats the significance of this? The average United States citizen produces far more greenhouse gas emissions than the average Chinese person. The following images show changes in the Earth and organisms as a result of global warming: Figure 1.2, Figure (a) Breakup of the Larsen Ice Shelf in Antarctica in 2002 was related to climate warming in the region. (b) The Boulder Glacier has melted back tremendously since 1985. Other mountain glaciers around the world are also melting. The timing of events for species is changing. Mating and migrations take place earlier in the spring months. Species that can are moving their ranges uphill. Some regions that were already marginal for agriculture are no longer arable because they have become too warm or dry. What are the two major effects being seen in this animation? Glaciers are melting and vegetation zones are moving uphill. If fossil fuel use exploded in the 1950s, why do these changes begin early in the animation? Does this mean that the climate change we are seeing is caused by natural processes and not by fossil fuel use? Permafrost is melting and its extent de- creasing. There are now fewer summer lakes in Siberia. (a) Melting ice caps add water to the oceans, so sea level is rising. Remember that water slightly expands as it warms this expansion is also causing sea level to rise. (b) Weather is becoming more variable with more severe storms and droughts. Snow blanketed the west- ern United States in December 2009. (c) As surface seas warm, phytoplankton productivity has decreased. (d) Coral reefs are dying worldwide; corals that are stressed by high temperatures turn white. (e) Pine beetle infestations have killed trees in western North America The insects have expanded their ranges into areas that were once too cold. Warming temperatures are bringing changes to much of the planet, including California. Sea level is rising, snow pack is changing, and the ecology of the state is responding to these changes. Click image to the left or use the URL below. URL: 
 Question: warmer temperatures are causing coral reefs to
answer:

turn white.