To lift a load of 200 N a distance of 2 m an effort of 25 N must be applied over an inclined plane of length 16 m. What must be done to lift the load 6 m, using the same effort?

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.