Which of the following is an example of static friction? a) a hockey player shooting a puck into the goal. b)a marble rolling down a street c)rubbing sticks together to create a fire d)leaning against a rock to take a break.

Need asap ‼️ 20 pts which gravitational force field diagram is drawn correctly? (answers in pictures below)

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.

Which statement is the best definition of an atom? a) anything that has mass and occupies space. b) the smallest particle that has the properties of an element. c) a substance that cannot be broken down chemically into simpler substances. eliminate d) the smallest unit of a substance that exhibits all of the properties characteristic of that substance.