tormentor

thank you both for valuable clues and answers .

ops my bad

it is done really clever ,because when you take an object and put it infinitely far away from planet you get (- infinite) potencial energy when object is on planet the potecial energy is 0 so work done by oject is used to rise the potencial energy .

In the beginning i would like to thanks each person for the time spent in my topic . My question is have you read this book ? do you think that this book is good for someone who wants to become a doctor and hence pass well the school living exams .i was looking for similar topic but my research stood for nothing .

have you tried solving these problems or are you just lazy ?