Is it possible to stand upside down on a ceiling? without using any tools

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.

Aball horizontally thrown from a cliff at 8m/s

Avector of magnitude 2 cannot be added to a vector of magnitude 3 so that the magnitude of the resultant is a. zero b. 1 c. 3 d. 5 e. 7