The moon umbriel orbits uranus (mass = 8.68*10^25 kg) at a distance of 2.66*10^8 m. what is umbriel's orbital speed?

50.)the diagram below represents the wave fronts produced by a point source moving to the right in a uniformmedium. observers are located at points a and b.compared to the wave frequency and wavelength observed at point a, the wave observed at point b has a(1) higher frequency and a shorter wavelength(2) higher frequency and a longer wavelength(3) lower frequency and a shorter wavelength(4) lower frequency and a longer wavelength