1 more question anyone know why it says to select brainliest but when I go to it to mark one as brainliest or whatever, it doesn't let me. does anyone know why?

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.