Which are the simplest pure substances that cannot be broken down into any other substances

Amira pulls a 3 pound wagon 4 feet. how much work has she done?

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

A1.5m wire carries a 2 a current when a potential difference of 52 v is applied. what is the resistance of the wire?