Military personnel also use periscopes in some gun turrets and in armoured vehicles. More complex periscopes using prisms or advanced fibre optics instead of mirrors and providing magnification operate on submarines and in various fields of science
Answer:
Explanation:
Given that the airplane starts from the rest (this is initial velocity equals to zero) and accelerates at a constant rate, position can be described like this: 
where x is the position, t is the time a is the acceleration and 
is initial velocity. In this way acceleration can be found. 
.
Now we are able to found velocity at any time with the formula: 
It will travel slowest through gases.
The mass of an object always stays the same since it is really just the amount of matter in an object so no matter the force applied, as long as the object does not lose or gain matter, the object stays the same
