In normal fission reactors, the fuel used to start the nuclear fission is Uranium-235.
Generally, fuel rods enriched with uranium-235 are used to start the fission. When a nucleus of uranium-235 absorbs a neutron, it becomes unstable and then it breaks apart, producing two smaller nuclei, several neutrons and energy. The additional neutrons produced in the reaction are then absorbed by other nuclei of uranium-235, triggering other fission reactions, and so on.
B. Kinetic energy increases, potential energy decreases.
Answer:
Acceleration = 9.8 m/sec2
Explanation:
We know that the acceleration due to gravity is 9.8 m/sec2 near the surface of earth.
Remember that the gravity is always affecting everything on earth at every instant, even the rock at the very top of it's trajectory. It doesn't mind if the velocity is zero for an instant or if there's air resistance, the gravity force is there, and always aims towards the center of the earth.
So for all the trajectory of the rock, gravity is 9.8 m/sec2
The planets have (their) moons. So the answer would be planets.