According to Newton's second law of motion, if we have a rigid, unchanging mass and we observe it accelerating, what must be happening? Question 15 options: A force is being applied to the mass No force was or is being applied to the mass The mass MUST be changing A force was not applied.

What do you think car designers do if the damage caused by a crash test is too severe?

Which branches of natural science include the study of an organism that lived 10 million years ago

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.