Sorry I just need to answer
answer
the final velocity is half of train car B's initial velocity
explanation
the conservation of momentum states that the initial and final total momentum are equal
m1v1 + m2v2 for initial momentum
(m1 + m2)v3 for final momentum because both cars stick together so their masses are combined
m1v1 + m2v2 = (m1 + m2)v3
since the mass of both are the same, m1 = m2
m1v1 + m1v2 = (m1 + m1)v3
m1(v1 + v2) = 2m1v3
divide both sides by m1
v1 + v2 = 2v3
since train car A is initially at rest, v1 = 0
v2 = 2v3
v3 = v2 * 1/2
the final velocity is half of train car B's initial velocity
<h3><u>Question: </u></h3>
The equation for the speed of a satellite in a circular orbit around the Earth depends on mass. Which mass?
a. The mass of the sun
b. The mass of the satellite
c. The mass of the Earth
<h3><u>Answer:</u></h3>
The equation for the speed of a satellite orbiting in a circular path around the earth depends upon the mass of Earth.
Option c
<h3><u>
Explanation:
</u></h3>
Any particular body performing circular motion has a centripetal force in picture. In this case of a satellite revolving in a circular orbit around the earth, the necessary centripetal force is provided by the gravitational force between the satellite and earth. Hence
.
Gravitational force between Earth and Satellite: 
Centripetal force of Satellite :
Where G = Gravitational Constant
= Mass of Earth
= Mass of satellite
R= Radius of satellite’s circular orbit
V = Speed of satellite
Equating
, we get
Speed of Satellite 
Thus the speed of satellite depends only on the mass of Earth.