Auth­ors of a new stu­dy, pub­lished in the jour­nal of the amer­i­can med­i­cal as­socia­t­ion, noted that old­er peo­ple with bet­ter cardio-respiratory fit­ness ap­pear to live long­er than un­fit ones. better cardio-respiratory fitness can be linked directly to

A1-lb collar is attached to a spring and slides without friction along a circular rod in a vertical plane. the spring has an undeformed length of 5 in. and a constant k =25 lb/ft. knowing that the collar is released from being held at a determine, the speed of the collar and the normal force between the collar and the rod as the collar passes through b.