If you take a fluid (i.e. air or water) and heat it, the portion that is heated usually expands. The same mass takes up more volume and as a consequence the heated portion becomes less dense than the portion that is<span><span> not heated.</span> </span>
Answer:

Explanation:
Given that
Mass of rifle = M
Initial velocity ,u= 0
Mass of bullet = m
velocity of bullet = v
Lets take final speed of the rifle is V
There is no any external force ,that is why linear momentum of the system will be conserve.
Initial linear momentum = Final linear momentum
M x 0 + m x 0 = M x V + m v
0 = M x V + m v

Negative sign indicates that ,the recoil velocity will be opposite to the direction of bullet velocity.
Explanation:
A lever is a rigid bar which moves freely about a fixed point called fulcrum....
The types of lever are :
- First class lever
- Second class lever
- Third class lever....
Explanation:
The given data is as follows.
m = 5000 kg, h = 800 km = 
, r = R + h = 
kg, G = 
As we know that,

v = 
And, it is known that formula to calculate angular velocity is as follows.

v = 
= 
= 
Thus, we can conclude that speed of the satellite is
.
the answer is True you can convert matter and energy