Diving can be done well or poorly, depending on how good the diver is. Sometimes, beginning divers will do "belly flops", smacking the water horizontally instead of cutting into it like a needle. Whether a dive is a good one usually depends on whether the diver went straight into the water or not. Experienced divers can do this without thinking much about it, as if it were like walking; beginners, however, have a lot more trouble. In time, people get used to diving; machines, however, can't learn, and are always just as clumsy. If the machine contained a computer, it would need a computer program to help it dive. The program would need to use a math formula. Here's what we'll start out with: v 1 = v 2 tan θ , where v 1 and v 2 represent forward and downward velocities, and θ is the vertical angle in degrees. Here's how it works: the forward and downward velocities of a good dive have the same ratio as the sine and cosine of the vertical angle of the di