Because there is no record of all things. As we have partially unknow information, it can never be held as a fact.
Answer:
thermal, hot equals thermal and such
Answer:

Explanation:
We have,
Mass of Mars is, 
Mass of its moon Phobos, 
Distance between Mars and Phobos, d = 9378 km
It is required to find the gravitational force between Mars and Phobos. The force between two masses is given by

Plugging all values, we get :

So, the gravitational force is
.
Answer:Decreases
Explanation:
Given
Volume is held constant that is it is a isochoric process.
We know that
PV=nRT
as n,V& R are constant therefore only variables are
P & T
so 

As
is decreasing therefore Pressure must also decrease so that ratio remains constant.
There was no net force on the stuffed toy, because the kids might have the same strength, The same force is on both sides of it. T<span>hey cancel each other out. They exert a force on the stuffed toy equal in strength but opposite in direction. The forces are balanced and the stuffed toy does not move. </span>Its like a game of tug-o-war, but you and I have the same strength. the rope would be still and not moving.