What creative thoughts did rømer have to explain his measurements

Which articulations allow for greatest range of motion?

An insulated 40 ft^3 rigid tank contains air at 50 psia and 120°f. a valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. the air temperature during this process is kept constant by an electric resistance heater placed in the tank. determine the electrical work done during this process.

What is the magnitude of the gravitational force acting on the earth due to the sun?