The superior and inferior vena cava are collectively called the venae cavae. The venae cavae, along with the aorta, are the great vessels involved in systemic circulation. These veins return deoxygenated blood from the body into the heart, emptying it into the right atrium.
The density of seawater plays a vital role in causing ocean currents and circulating heat because of the fact that dense water sinks below less dense. long story short, seawater is the problem because its denser than pure water.
Answer:
Force = mass × acceleration.
Answer:
Force of gravity, F = 0.74 N
Mass of an object, m = 1.2 kg
Distance above earth's surface, 
Mass of Earth, 
Radius of Earth, 
We need to find the force of gravity above the surface of Earth. It is given by :

R = r + d
R = 25370000 m

F = 0.74 N
So, the force of gravity on the object is 0.74 N. Hence, this is the required solution.