Acceleration because it is at a rise in speed. The formula for acceleration is Speed/Time.
First we gotta use an equation of motion:

Our vertical distance d= 100 m, initial vertical speed u = 0 m/s (because velocity is fully horizontal), and vertical acceleration a = 9.8 m/s2 because of gravity. Let's plug it all in!

Now we just need to solve for t:

Hit the calculators, and you'll get 4.5 seconds!
<span>The expected boiling point of a substance increases with an increasing molar mass of the substance. So I would expect the lighter compounds to boil at lower temperature. Also more polar molecules tend to boil at higher temperature.
Pentane is the lightest of all three compounds, so it should boil the soonest.
Heptane is a lot heavier than Pentane, but slightly lighter than Heptanol. So it should boil next.
Heptanol is the heaviest of all of the molecules and is also quite polar compared to heptane. So it should have the highest of all the boiling points.</span>
Gamma Rays Hope This Helps