4. Explain the function of the spring floor with respect to Newton’s first law for linear motion with respect to conservation of linear momentum
(mGvG-MSFVSF) = (mGvG-MSFVSF) before contacting after contacting floor for take-off floor for take-off

I think that the conservation of mechanical energy is very important in this section, probably more so than conservation of momentum. Momentum is conserved only for the short time during which the impact of the diver on the springboard first occurs. Otherwise, when the diver is rising of falling, or the springboard is changing shape, energy conservation must be used, in the form (KE + PE)1 = (KE + PE)2, where subscripts 1 and 2 refer to two different times. For example, energy is conserved while the diver is in the air, and this allows you to relate the maximum height to the velocity when the diver hits.
Then the kinetic energy of the diver and the board are related to the maximum deformation of the board, because this deformation gives the board potential energy.