Physics Chapter 10
Is it possible for a system to have negative potential energy?
Yes, since the choice of the zero of potential energy is arbitrary
A shell explodes into two fragments, one fragment 25 times heavier than the other. If any gas from the explosion has negligible mass, then
the momentum change of the lighter fragment is exactly the same as the momentum change of the heavier fragment
In an INELASTIC collision between two objects
the momentum of the system is conserved but the kinetic energy of the system is not conserved
A baseball is thrown vertically upward and feels no air resistance. As it is rising
its momentum is not conserved, but its mechanical energy is conserved
Jacques and George meet in the middle of a lake while paddling in their canoes. They come to a complete stop and talk for a while. When they are ready to leave, Jacques pushes George's canoe with a force to separate the two canoes. What is correct to say about the final momentum and kinetic energy of the system if we can neglect any resistance due to the water?
the final momentum is in the direction opposite of F but the final kinetic energy is zero
On a smooth horizontal floor, an object slides into a spring which is attached to another mass that is initially stationary. When the spring is most compressed, both objects are moving at the same speed. Ignoring friction, what is conserved during this interaction?
momentum and mechanical energy
A 1.0-kg block and a 2.0-kg block are pressed together on a horizontal frictionless surface with a compressed very light spring between them. They are not attached to the spring. After they are released and have both moved free of the spring
the lighter block will have more kinetic energy than the heavier block
Consider a plot of the displacement (x) as a function of the applied force (F) for an ideal elastic spring. The slope of the curve would be
the reciprocal of the spring constant
In a perfectly ELASTIC collision between two perfectly rigid objects
both the momentum and the kinetic energy of the system are conserved