according to "why do some brains enjoy fear?" what feeling do many people commonly have after a frightening experience, such as touring a haunted house?

Does indrect sunlight does not pose any danger to the skin

This is one popular brand of exercise machine

The famous scientist galileo galilei did several experiments with sloping planes, which he rolled metal balls down so that he could study motion. by changing the slope, he could study how the speed at which the ball rolled was affected. what was the dependent variable in galileo's experiment?