Which of the following questions could best be answered by the work of Charles Kuen Kao?
A. How are mirrors used inside a camera?
B. How quickly are stars in the Milky Way moving away from Earth?
C. What is the best way to deliver broadband Internet service to rural
areas?
D. How will climate change affect the strength of hurricanes in the
future?

Suppose a force of 60 n is required to stretch and hold a spring 0.1 m from its equilibrium position. a. assuming the spring obeys hooke's law, find the spring constant k. b. how much work is required to compress the spring 0.5 m from its equilibrium position? c. how much work is required to stretch the spring 0.6 m from its equilibrium position? d. how much additional work is required to stretch the spring 0.1 m if it has already been stretched 0.1 m from its equilibrium? a. kequals 600