6) (From Page 11) If a small motor does 520 J of work to move a toy car 260
m, what force does it exert?
point
0 135,200 N
O 2N
O 05
O 780N -
7) (From Page 12) A block is sitting on a platform 20 m high. It weights 50
kg. How much Potential energy does it contain?
1000

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