Two Main Forces Involved In Nuclear Fusion
The two main forces involved in nuclear fusion are the electromagnetic force and the strong nuclear force. The repulsive electromagnetic force between positively-charged nuclei is long range but relatively weak while the nuclear force is short range but much stronger. When the two nuclei are far enough apart, the repulsive electromagnetic force dominates, holding the nuclei apart. As the two nuclei get closer the electromagnetic repulsion gets stronger and more difficult to push the nuclei together. When the two nuclei approach and get closer to each other, the nuclear force dominates and the two nuclei fuse together to form a new nucleus. This requires a lot of pressure, provided by gravity caused by mass to push nuclei together in short-range