(a) 0.448
The gravitational potential energy of a satellite in orbit is given by:

where
G is the gravitational constant
M is the Earth's mass
m is the satellite's mass
r is the distance of the satellite from the Earth's centre, which is sum of the Earth's radius (R) and the altitude of the satellite (h):
r = R + h
We can therefore write the ratio between the potentially energy of satellite B to that of satellite A as

and so, substituting:

We find

(b) 0.448
The kinetic energy of a satellite in orbit around the Earth is given by

So, the ratio between the two kinetic energies is

Which is exactly identical to the ratio of the potential energies. Therefore, this ratio is also equal to 0.448.
(c) B
The total energy of a satellite is given by the sum of the potential energy and the kinetic energy:

For satellite A, we have

For satellite B, we have

So, satellite B has the greater total energy (since the energy is negative).
(d) 
The difference between the energy of the two satellites is:

Luster I think is what you are looking for
Explanation:
In order to find out if the keys will reach John or not, we can use the formula of projectile motion to find the maximum height reached by the keys:
H = V²Sin²θ/2g
where,
V = Launch Speed = 18 m/s
θ = Launch Angle = 40°
g = 9.8 m/s²
Therefore,
H = (18 m/s)²[Sin 40°]²/(2)(9.8 m/s²)
H = 6.83 m
Hence, the maximum height that can be reached by the projectile or the keys is greater than the height of John's Balcony(5.33 m).
Therefore, the keys will make it back to John.
<h3><u>Answer;</u></h3>
Satellite
Differences in ocean-surface height can be measured by<u> Satellite</u>
<h3><u>Explanation;</u></h3>
- The topography of the ocean or the height of the ocean surface relative to a level of no motion provides the information on tides, and the distribution of heat and mass in the Earths's oceans.
- <em><u>The ocean topography is measured using satellites altimeter. Satellites use radar altimeters that are specially made to measure the height of the ocean surface. The satellites measure the height of the ocean surface with an accuracy of 3 cm relative to the center of the earth.</u></em>
- Satellite altimeter combines precise orbit determination with accurate ranging by a microwave altimeter of ocean distance to the satellite.