Answer: A piston-filling fountain pen has a piston — just like in a car — inside the barrel. This piston goes down to expel air or ink and then back up, pulling ink into the barrel. The typical process is very simple, assuming the pen is clean and dry: Push the piston down, expelling any air in the barrel
Explanation:
Light Light from a moving source travels at 300,000 km/sec (186,000 miles/sec).
Note:
The Speed of Light Is Constant.
Answer:
Absolute pressure of the oil will be 102822.8 Pa
Explanation:
We have given height h = 31 cm = 0.31 m
Acceleration due to gravity 
Specific gravity of oil = 0.600
So density of oil 
We know that absolute pressure is given by
, here 
So absolute pressure will be equal to 
So absolute pressure of the oil will be 102822.8 Pa
Unless if all forces cancel each other out , the object will no longer be in equilibrium