Which of the following phenomenon odd called photoelectric effect? A. High energy electrons impinge on a metallic Annie which emits electrons

B. A high energy photon emits photons as it slows down

C. A metal absorbs a quanta of light and then emits electrons

D. Two electrons are created from a quanta of light.

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