题目

This story happened when I was in Saint Lucia with my family. My sister, Diana, who also happens to be my best friend and one of the funniest and kindest people I know, went blind in one eye about 9 years ago. Diana sometimes feels concerned about the way her eye looks now. The pupil(瞳孔) is no longer black; it’s sort of “glows” in photos. Diana recently purchased a special contact lens(隐形镜片) that makes her eye look like it did before it changed color, but she doesn’t wear this lens often because it becomes quite painful after about an hour.One night during our holiday, a ho如图所示，某同学在10秒内用力F通过滑轮将重力为200牛的物体匀速升高2米，不计绳重和摩擦，求：①力F做的功W．②力F的功率P．