I believe the answer is option A
The energy of a single photon is given by:

where
E is the energy
h is the Planck constant
f is the frequency of the light
The light in our problem has a frequency

, so the energy of each photon of that light is:
The two satellites orbit around the same planet, so we can use Kepler's third law, which states that the ratio between the cube of the radius of the orbit and the orbital period is constant for the two satellites:

where

is the orbital radius of the first satellite

is the orbital radius of the second satellite

is the orbital period of the first satellite

is the orbital period of the second satellite
If we use the data of the problem and we re-arrange the equation, we can calculate the orbital period of the second satellite:
Answer:
Her speed is 9.8 meter per second
Explanation:
Newton's second law states that acceleration (a) is related with force (F) by:
(1)
Here the only force acting on the firefighter is the weight F=mg so (1) is:
Solving for a:

Now with the acceleration we can use the Galileo's kinematic equation:
(2)
With Vf the final velocity, Vo the initial velocity and Δx the displacement, because the firefighter stars from rest Vo=0 so (2) is:

Solving for Vf


Answer:
C
Explanation:
There's a reason newton's 3rd law is called action-reaction :D
A - 1st law/inertia
B - 2nd law/f=ma