placing a magnetically hard material in a strong magnetic field
B because the skater is constantly moving in the same speed to go in a circle .
Earth sits motionless in the universe at the center of a revolving globe of starts , with the moon and planets in orbit around the earth, is the surrounding model of the uninverse
Infrared, visible light, then ultraviolet. Infrared is light that the human eye can not see and visible light is clearly light we can see then ultraviolet is has such a high frequency we can't see it either.