The time it took her to drive 2 km is 11.43 seconds, because sonverting kilometers to meters, it is 1000 meters to every kilometer, and she travels 2 kilometers, which is two-thousand meters. Then to find the time you need to divide the time by the speed, and with that you get 11.4285714286, or 11.43 seconds.
Sound energy is produced when an object vibrates. The sound vibrations cause waves of pressure that travel through a medium, such as air, water, wood or metal. Sound energy is a form of mechanical energy. (I believe this is it)
Answer: Hydrogen molecules will have greatest average speed.
Explanation:
The formula for average speed is :

R = gas constant
T = temperature
M = Molecular Mass
Now putting all the values:



Thus average speed of hydrogen is 8 times the average speed of oxygen. Thus hydrogen molecules will have greatest average speed
Answer:
Boron has a larger radius and the protons in carbon exert more pull.
Explanation:
Remember than elements have greater radius as they are closer to the bottom left corner, so boron would have the larger radius here. Carbon has a smaller radius, which makes it easier for the protons in carbon to exert more pull.
Answer:
True
Explanation:
Fossil age can determine organism changes related to the time scale. Fossils provide scientists with evidence that allows them to hypothesize how living organisms have evolved over time.
fossil can be studied to determine what kind of organism it represents, how the organism lived, and how it was preserved. However, by itself a fossil has little meaning unless it is placed within some context. The age of the fossil must be determined so it can be compared to other fossil species from the same time period. Understanding the ages of related fossil species helps scientists piece together the evolutionary history of a group of organisms.