even if the sledge is considered massless (as assumed in the problem) : the problem uses change in momentum to calculate force after 20 s there is no change in momentum so no force applied as we know no force acts on a massless body but it will have its velocity so it should be covering the remaining distance with a constant velocity taking a total of 38 sec
I am only one,
But still I am one.
I cannot do everything,
But still I can do something;
And because I cannot do everything
I will not refuse to do the something that I can do.
- Edward Everett Hale
Moderation Team
![[Post New]](/templates/default/images/icon_minipost_new.gif){kind=icon}
![[Up]](/templates/default/images/icon_up.gif "[Up]"){kind=icon}
120
