做功(题目是英语的)..能帮的麻烦进来解答

题目

做功(题目是英语的)..能帮的麻烦进来解答
A water skier is pulled by a string and slides on an inclined platform at a uniform speed of 10 ms^-1.The tension in the string is 375N.Assume the tension is the string is parallel to the displacement of the skier.
(a)How much work has the tension done on the water skier for 1s?
(b)How much kinetic energy does the skier gain 1s?explain briefly.
在 题(b) ..可以用中文...还有一个问题就是 如果 力F 对一个物体 做功 ...那个物体的动能一定会起 增加或减少...因为做功的定义是 The amount of energy transferred in such process is called Work

答案

(1) Work is defined as W = F.S cos(theta) since theta = 0 (Ok,you could argue that it could as well be 180,but it is just not commonly seen.),hence W = 375 * 10m/s *1s * 1 = 3750 J(2).Since the water ...