# Unusual difficult kinetic problem

• dirk_mec1
In summary, the conversation discusses the process of using an energy balance and conservation of momentum to find a differential equation for the change in momentum of a rocket's exhaust gases over time. The equations used are the general kinetics formulas, and the conversation provides a step-by-step approach to solving the problem.
dirk_mec1

## Homework Statement

http://img80.imageshack.us/img80/1797/20799357.png

## Homework Equations

General kinetics formulas

## The Attempt at a Solution

Actually I don't know how to start. The initial mass is M when qm energy is used the mass is M-m. If I use an energy balance I must use the integral version, right?

$$\int m(t) v \mbox{d}v = qm$$

But I don't know how to start.

Last edited by a moderator:
I myself have never done this before, but I will try to help you. I think my way should get the required formula.

Consider the exhaust gases (a small amount 'dm') at time 't'.

Initial momentum pt= dm*ve

Final momentum pt+dt = dm(vR-ve)

Rocket:

pt=(M-dm)vR
pt+dt= (M-dm)(vR-ve).

Now use conservation of momentum here: Loss in change of momentum in gas = change momentum gained by rocket

Using this, you should now be able to get a differential equation to solve (remember, 'dm' is infinitesimally small)

## What is an "Unusual difficult kinetic problem"?

An unusual difficult kinetic problem is a scientific problem that involves the study of the rates of chemical reactions and the factors that affect these rates. These problems are often complex and challenging to solve due to the unique nature of the system or reaction being studied.

## What makes a kinetic problem "unusual" or "difficult"?

An unusual or difficult kinetic problem can be characterized by several factors, including the complexity of the reaction mechanism, the presence of multiple reaction pathways, the involvement of intermediate species, or the use of non-standard conditions or techniques.

## What are some common techniques used to solve unusual difficult kinetic problems?

Some common techniques used to solve unusual difficult kinetic problems include spectroscopy, computational modeling, and kinetic measurements using specialized equipment such as stopped-flow or flow-injection analysis systems.

## Why is it important to study unusual difficult kinetic problems?

Studying unusual difficult kinetic problems can provide valuable insights into the fundamental principles of chemical reactivity, as well as practical applications in fields such as drug discovery, materials science, and environmental remediation. These problems also challenge scientists to develop new methods and techniques for understanding and controlling chemical reactions.

## What are some current research areas in the study of unusual difficult kinetic problems?

Current research areas in the study of unusual difficult kinetic problems include the development of new catalysts and reaction pathways, the investigation of reaction mechanisms in biological systems, and the use of kinetic modeling to predict and optimize reaction rates in industrial processes.

Replies
13
Views
486
Replies
2
Views
328
Replies
4
Views
896
Replies
8
Views
1K
Replies
4
Views
879
Replies
8
Views
3K
Replies
29
Views
2K
Replies
3
Views
1K
Replies
1
Views
590
Replies
22
Views
3K