Answer:

Explanation:
It is given that,
A planar electromagnetic wave is propagating in the +x direction.The electric field at a certain point is, E = 0.082 V/m
We need to find the magnetic vector of the wave at the point P at that instant.
The relation between electric field and magnetic field is given by :

c is speed of light
B is magnetic field

So, the magnetic vector at point P at that instant is
.
The centripetal force needed to keep earth in orbit is gravity.