Two objects are moving about so that their total momentum is zero. What can be said about their kinetic energy?

When the total momentum of two objects is zero, it means that the objects have equal and opposite momenta. In other words, their individual momenta cancel each other out. Since momentum is directly proportional to the velocity of an object, this implies that the two objects are moving in opposite directions with the same speed.

Now, let's analyze the kinetic energy of the two objects.

The kinetic energy of an object is given by the equation: K.E. = (1/2)mv^2, where m is the mass of the object and v is its velocity.

Since the objects have equal and opposite momenta, their masses can be equal or different. Let's consider two scenarios:

Scenario 1: The masses of the objects are equal.
In this case, since the objects have equal momenta, they also have equal velocities. Therefore, the kinetic energy of both objects will be the same.

Scenario 2: The masses of the objects are not equal.
In this case, since the momenta are equal and opposite, the object with a larger mass will have a smaller velocity compared to the object with a smaller mass. In other words, the object with a larger mass will have less kinetic energy compared to the object with a smaller mass.

In summary, when two objects have a total momentum of zero, their kinetic energies will be equal if their masses are equal. If their masses are not equal, the object with a larger mass will have less kinetic energy than the object with a smaller mass.

To determine the specific values of their kinetic energies, you would need to know the masses and velocities of the objects.