Understanding questions (6 points) explain in your own words why it is important to understand the synchronization of clocks! state the two postulates einstein used for his theory of special relativity! under what conditions do the lorentz-transformations equal the galilean transformations? a) b) c)

Glass is transparent to visibile light under normal conditions; however, at extremely high intensities, glass will absorb most of the light incident upon it. this works through a process known as multiphoton absorption. in this process, several photons are absorbed at the same time. if very intense light whose photons carry 2ev of energy is shined onto a material with a band gap of 4ev, that light can be absorbed through two-photon absorption, because two photons have the right amount of energy to bridge the band gap. what is the minimum number of photons of 800-nm light that are needed to equal or exceed the band gap of fused silica glass

3. a lunar exploration vehicle was created by a research team. it weighs 3,000 kg on the earth. it needs an acceleration of 10 m/s2 on the moon. in order to have the same acceleration, what will be the net force acting on the vehicle on the earth?

City b is south of city a, and the 200 mile trip by car takes 4 hours. the cities are 120 miles apart in a straight line. what is the velocity of a trip from city a to city b?