In other words, find an orbit with a period of 24 hours. Recalling the relationship between force and period of circular motion, the period, radius and mass of the satellite are related to the ...

We can measure the radius because the proton's charge is spread across it, which influences the orbit of any electrons that might be circling it. Measurements with electrons produce a value that's ...

Because we know the radius of the Earth ... the centripetal force needed to keep the earth in its (almost circular) orbit around the sun. The centripetal force is the Earth's mass times the ...