Weight is a force caused by gravity. The weight of an object is the gravitational force between the object and the Earth. The more mass the object has the greater its weight will be.
1km=10^3 m,1km^3=10^9cubic metres answer is 1.4x10^18cubic meters
The correct statement is
Ultraviolet light has both a higher frequency and a higher radiant energy than visible light.
because ultraviolet light has wavelength smaller than the visible light hence has a greater frequency as compared to visible light. (frequency is inversely related to wavelength. hence smaller the wavelength , greater will be the frequency)
we also know that the radiant energy is directly proportional to the frequency. hence greater the frequency , greater will be the radiant energy.
Since the frequency is greater for ultraviolet light , it radiant energy is also greater