Answer:
the similarity is that hands are applied and force
Even though the object is weightless, it would need inertia, I.e, you pushing it or any form of transportation. So you would still have to push that 500kg to just keep it moving in space. Say if it were a planet with less gravitational force, it would be weightless.
1. Single dental x-rays: 
The energy of the photon is

Using the conversion factor

we can convert it into Joules:

The relationship between photon energy and wavelength is

where
is the Planck constant
is the speed of light
E is the energy
Substituting into the formula, we find

2. Microtomography: 
The energy of these photons is 2.5 times greater, so

And by applying the same formula used at point 1, we find the corresponding wavelength:
