can a system whose momentum is conserved be made up of smaller systems whose individual momenta are not conserved?

Look at the potential energy diagram for a chemical reaction. which statement correctly describes the energy changes that occur in the forward reaction?

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is

If the radius of curvature of the cornea is 0.75 cm when the eye is focusing on an object 36.0 cm from the cornea vertex and the indexes of refraction are as described before, what is the distance from the cornea vertex to the retina? express your answer to two significant