Suppose you illuminate two thin slits by monochromatic coherent light in air and find that they produce their first interference minima at ± 35.05 ∘ on either side of the central bright spot. You then immerse these slits in a transparent liquid and illuminate them with the same light. Now you find that the first minima occur at ± 19.30 ∘ instead. a) What is the index of refraction of this liquid?
Express your answer using four significant figures.

Could someone me find the answer to this problem.

A2k pendulum has a speed of 1 m/s at a height of 1/2 meter

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