so eventually i started stopping after he got to 20 or so. thank you so much i will be placing my order this afternoon for the combination that you suggest and will likely add the 25 foot just to have that additional flexibility. his previous water bottle finally had to be disposed of and he’s been using mine. 14. what is the net force on a bag pulled down by gravity with 18 newtons and pulled upward by a rope with 18 newtons? emotions will run high throughout the festive season. 