Answer:
Acceleration due to gravity will be 
Explanation:
We have given length of pendulum l = 55 cm = 0.55 m
It is given that pendulum completed 100 swings in 145 sec
So time taken by pendulum for 1 swing 
We have to find the acceleration due to gravity at that point
We know that time period of pendulum;um is given by

So 

Squaring both side


So acceleration due to gravity will be 
A. 2 S O 2, gas, plus O 2, gas, in equilibrium with 2 S O 3, gas.
B is the answer for your question the answer is b an elevator slowing down
Reactants
C8H18
O2
Products
CO2
H2O