Explanation:
Eq 2 ) is Equation for force on a charge Q1 due to charge Q2 separated by a distance R .. it is Equation for Coloumb's law !!
Where , k = 1/4π€
Eq 3 ) is Equation for force on mass m1 due to mass m2 separated by distance R .. it is Newton's law of Gravitation
Where , G = universal Gravitation constant
Answer:
C
Explanation:
force equals mass time acceleration
I added individual steps for clarity. Note that g must be positive if the solution is to be real.

Let me know if you have any questions.
We use the kinematic equation of motion, to calculate the average acceleration

or 
Here,
is initial speed , v is final speed h is covered distance
is initial position.
Given
,
,
and
.
Substituting these values in above equation we get,

Thus, the average acceleration of the sprinter is
.
Answer:
The observed wavelength on Earth from that hydrogen atom is
.
Explanation:
Given that,
The actual wavelength of the hydrogen atom, 
A hydrogen atom in a galaxy moving with a speed of, 
We need to find the observed wavelength on Earth from that hydrogen atom. The speed of galaxy is given by :

is the observed wavelength

So, the observed wavelength on Earth from that hydrogen atom is
. Hence, this is the required solution.