1. Assume Earth and a cloud layer 800.0 m above the Earth can be treated as plates of a parallel-plate capacitor. a. If the cloud layer has an area of 1.00 106 m², what is the capacitance? b. If an electric field strength of 2.0 x 106 N/C causes the air to conduct charge (lightning), what charge can the cloud hold? c. Describe what must happen to its molecules for air to conduct electricity.​

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