Calculating the Speed of Exhaust Gas for a Rocket in Deep Space

  • Thread starter Thread starter ch010308
  • Start date Start date
  • Tags Tags
    Rocket Space
AI Thread Summary
The discussion revolves around calculating the speed of exhaust gas from a rocket in deep space, given its acceleration and mass ejection. The conservation of momentum equation is applied, but the user struggles to isolate the speed of the exhaust gas due to the presence of the rocket's velocity in the equation. Clarification is sought on how to approach the problem, particularly regarding the use of the formula F = m*a and its relation to momentum change. Ultimately, the user finds understanding after receiving guidance on the correct application of the equations. The conversation highlights the complexities of momentum conservation in rocket propulsion scenarios.
ch010308
Messages
9
Reaction score
0

Homework Statement



A rocket is fired in deep space, where gravity is negligible. In the first second it ejects 1/160 of its mass as exhaust gas and has an acceleration of 15.9 m/s2.

What is the speed vgas of the exhaust gas relative to the rocket?
Express your answer numerically in kilometers per second.

Homework Equations



conservation of momentum: (m1v1 + m2v2)final = (m1v1 + m2v2)initial

The Attempt at a Solution



(159/160)M(vrocket + 15.9) - (1/160)Mvgas = Mvrocket

I go on to simplify it but I can't express vgas in numerical terms, as vrocket still remains in the equation. There is no value given for this so how can I solve the question?

Pls help! Thanks! :)
 
Physics news on Phys.org
What's wrong with F = m*a = Δmv/Δt ?
 
hmmm... Are you saying that i should use m*a = Δmv/Δt for the change in momentum of the rocket? then wat will be the value of m? :confused:
 
ooohh! I got it now! Thanks for the help! :)
 
Thread 'Voltmeter readings for this circuit with switches'

Thread 'Voltmeter readings for this circuit with switches'

TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
View full post »
Thread 'Correct statement about a reservoir with an outlet pipe'

Thread 'Correct statement about a reservoir with an outlet pipe'

The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
View full post »

Similar threads

Forces - Space Shuttle Takeoff Calculations
Replies
22
Views
2K
How Does Rocket Ejection Mass Affect Its Velocity in Space?
Replies
1
Views
2K
Force and acceleration of a rocket
Replies
3
Views
2K
How to calculate velocity of infinite-stage rocket?
Replies
2
Views
1K
I Is there a way to calculate how rocket exhaust gas spreads out in empty space after leaving the rocket?
Replies
3
Views
926
Motion of a rocket with propellant exhaust gas speed = constant
Replies
6
Views
1K
Principle of linear momentum for a rocket
Replies
6
Views
2K
Velocity of a single-stage rocket
Replies
10
Views
10K
Find velocity of rocket that obtains more gas from gas cloud
Replies
3
Views
1K
Model Rocket Launch: Maximum Height, Time, and Duration Calculations
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top