I do think that rich people do more work in general, and I say that because money is something you work to get, but I don't believe it is always physical work. Many rich people work in offices, such as lawyers, doctors, politicians etc... I think they do more work in the mental aspect.
I believe the lower you are in society, the more physical work you have to do to make ends meet. Likewise, the higher in society a person is, the less actual work they have to do. For instance, a factory worker in Bangladesh works 10 times harder than Donald Trump, but makes 1/100000 of his salary. This is made possible by the immoral capitalist system that temporarily has hold on human civilization. Capitalism is more advanced than Feudalism, but more primitive than Socialism.
No. I believe poor people often do more physical based work than rich people; however, I say this with a caveat. Rich people are often just as exhausted when they get home from work, as they work a great deal with their brain power. Working hard with the mind can be just as taxing as physical labor.