Jack tries to place magnets on the refrigerator but they wont stick. what could be the reason why

What happens to the light rays when they hit the specimen?

What is the weight of a feather (mass = 0.0001 kg) that floats through earth's and the moon's atmospheres?

Awater slide of length l has a vertical drop of h. abby's mass is m. an average friction force of magnitude f opposes her motion. she starts down the slide at initial speed vi. use work-energy ideas to develop an expression for her speed at the bottom of the slide. then evaluate your result using unit analysis and limiting case analysis. express your answer in terms of the variables h, m, l, vi, f and appropriate constants. vf v f