Which hydrocarbon will provide more heat when allowed to react with oxygen?

The answer to this question could be thermal energy, or energy.  Hydrocarbons are molecules consisting hydrogen and carbon that are most likely the primary constituent of fossil fuels like natural gas, petroleum, and coal.  Hydrocarbon combustion is the reaction where hydrocarbon reacts with oxygen to create carbon dioxide, water, and heat. 

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year