20N•m or 20J. Work is equal to force•distance, and 5N•4m is 20N•m, or J
Answer:

Explanation:
The energy of a photon is given by:

where
h is the Planck constant
c is the speed of light
is the wavelength of the photon
In this problem, we have a microwave photon with wavelength

Substituting into the equation, we find its energy:

Answer:
Explanation:
According to Newton's third law, every action has an equal and opposite reaction
so it tells us that the force exerted by the earth on the spacecraft is equal to the force exerted by the spacecraft on the earth. But we do not see the earth moving towards the spacecraft because the inertia of the spacecraft is very less than the inertia of the earth.