Which of the following should receive the most emphasis in a classroom management plan?

Lucas, a third-grader, enters his classroom for the first time and see that the desks are in rows. If you were Lucas, what conclusion might you draw about the nature of instruction in this class?  

A gun is made of a super-low-weight but strong material. The bullet for the gun is more massive than the gun itself. For such a gun

Consider a system containing three objects that move with different velocities. The objects can interact with each other through forces. In this system

A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction of motion. A force doing no work during the motion is

A bullet is fired into a wall and comes to rest. Considering only the bullet as the system we can say that

In this diagram a force acting on a block is shown by the arrow labeled F. The mass of the block is known, as is the size of the force, but the observed acceleration is larger than F/m and so another force must act on the block. In which direction (A, B, C, or D) is this force?

A pendulum swings through 10 cycles in 2 seconds. The frequency of the pendulum is

A single constant 10-pound force F1 acts on a body, causing it to accelerate. Then, while F1 continues to act, a second constant force F2 is applied to the body, which comes to a momentary stop. The magnitude of F2 is

A car rounds a curve while maintaining constant speed. Which of the statements is correct?