Please can anyone help with these questions they are very hard

Taylor's experiment: 1. accurately measured the speed of light 2. locked together the phases of two light sources so that the interference pattern would not shift 3. showed that man's reaction time was much slower than the speed of light 4. showed that individual photons have wave characteristics

The protons in a nucleus are approximately 2 ✕ 10^−15 m apart. consider the case where the protons are a distance d = 1.93 ✕ 10^−15 m apart. calculate the magnitude of the electric force (in n) between two protons at this distance.

Two trains leave a station at the same time, train a travels at a constant speed of 16 m/s. train b starts at 8.0 m/s but accelerates constantly at 1.0 m/s squared. after 10.0 seconds, which train has the greater speed?