math t calculus

數學神童

a ladder 5 m long leans against a vertical wall.the bottom of the ladder is pulled along the ground away from the wall at a constant rate of 0.3ms^-1.How fast will the top of the ladder be falling at the instant when its bottom is 2m away from the wall?
answer:0.13ms^-1

walrein_lim88

a ladder 5 m long leans against a vertical wall.the bottom of the ladder is pulled along the ground  ...
數學神童 发表于 18-1-2010 04:10 PM

sorry,答案应该-0.13m /s
因为跌下去的话，vertical height decreases ..