Answer:
a planet
Explanation:
a planet is one which exerts these properties and therefore is the answer
Answer:

Explanation:
From the question we are told that
Weight of fireman 
Pole distance 
Final speed is 
Generally the equation for velocity is mathematically represented as

Therefore Acceleration a
Generally the equation for Frictional force
is mathematically given as



Therefore

The Cell Membrane is what controls what enters and leaves the cell.
I think that mechanism is called a <em>"lens turret"</em>.