The refractive index of a certain type of glass is 1.2. What is the critical angle between the glass and air ? Show your work.

What do butterflies have on their feet which allows them to sense different strengths and types of nectar? a. mechanoreceptors b. acoustic receptors c. substratum receptors d. chemoreceptors

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects

This is important 1. what happens to the speed of molecules in water vapor when it condenses to form a liquid? (2 points) the molecules slow down. the molecules speed up. the molecules slow down and then speed up. the molecules speed up and then slow down. 2. how might human activities change to compensate for a decrease in water supplies? (2 points) humans might build a factory. humans might build drainage systems. humans might extract more water from the ground. human behavior does not change because of the water cycle. i'll be grateful if anyone can answer these 2 questions !