When you talk about rate, you will expect that it will be in terms of a time unit. It measures how fast it is going. So, you would expect that the denominator is in time units. For the movement, you can measure this with either distance or velocity.
So, for the first variety, you would need distance and time to measure the rate of how far you go at a certain time. It is also called as velocity. For the second variety, you would need velocity and time to measure the rate of how fast you are going at a certain interval. It is also called as acceleration.
Are you referring to the fact that water is a compound while hydrogen is an element? If I'm wrong just comment and clarify and I can edit it, I don't even know what kind of unit you're in. :)
Antoine-Laurent Lavoisier was the first person to report the four element classification system but also ended up including some compounds rather than elements.
Answer: 148348.6239 kg•m/s
Explanation: Firstly, we need to convert the 14700 N into kilograms, and to do so, use the formula net force is equal to mass times acceleration and rearrange the formula to find mass like shown below...
F = ma
F/a = m
14700/9.81 = 1498.470948 kg, this is your mass
Now that we convert it into kilograms, plug all the numbers into the variable of the momentum formula.
Momentum formula is P = mass x velocity
Like this:
P = 1498.470948 x 99
p = 148348.6239 kg•m/s.
I believe that is your answer, hope that helps you even a bit out.
Thanks.