Torque Provided By A Rocket's Thrust

  • Thread starter Thread starter cjavier
  • Start date Start date
  • Tags Tags
    Thrust Torque
Click For Summary
SUMMARY

The discussion centers on calculating the angular acceleration of a model rocket generating 4.0 N of thrust while attached to a 100 g rigid rod. The user initially questions the omission of torque from the rod's gravitational pull in the total torque calculation. However, it is clarified that since the rocket moves in a horizontal circle, the gravitational forces acting on the rod and rocket are balanced by the supporting structure, thus not contributing to the total torque. The resolution confirms that the focus should remain on the thrust and the moment of inertia of the system.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Familiarity with torque and angular acceleration concepts
  • Knowledge of moment of inertia calculations
  • Basic principles of circular motion
NEXT STEPS
  • Study the relationship between torque and angular acceleration in rigid body dynamics
  • Explore the concept of moment of inertia for composite bodies
  • Learn about the effects of gravitational forces on rotating systems
  • Investigate the principles of circular motion and centripetal force
USEFUL FOR

Physics students, educators, and hobbyists interested in model rocketry and dynamics, particularly those looking to deepen their understanding of torque and angular motion in practical applications.

cjavier
Messages
17
Reaction score
0
The Question Is: The 200 g model rocket shown in the figure generates 4.0 N of thrust. It spins in a horizontal circle at the end of a 100 g rigid rod. What is its angular acceleration? Here is the picture:

http://session.masteringphysics.com/problemAsset/1073775/3/knight_Figure_13_24.jpg

However, I am confused that every answer I have seen does not take into account the torque generated by the rod's gravitational pull to produce the Total Torque (Sigma Torque). Why is this?

PLEASE do not just post to me how to get the answer. I have seen this. I also realize that the moment of inertia take's into account the rod. However, I still believe that the gravitational pull of the rod should be accounted for in the total torque. Please, someone with experience explain to me why this is not so.
 
Physics news on Phys.org
You are told that the rocket moves in a horizontal circle, so somehow the torque from the weight of rocket plus rod has already been balanced by the supporting structure.
 
Question Resolved

HORIZONTAL. I see now. Thank you
 

Similar threads

Why is the thrust equation same under gravitational force?
  • · Replies 10 ·
Replies
10
Views
2K
Questioning My Understanding: Is My Answer Wrong?
  • · Replies 40 ·
2
Replies
40
Views
4K
Torque and rotation around a fixed point
  • · Replies 18 ·
Replies
18
Views
5K
Shear: What would be the equation for ''pure'' torque?
  • · Replies 9 ·
Replies
9
Views
2K
Force and acceleration of a rocket
  • · Replies 3 ·
Replies
3
Views
2K
Rotational Motion Question, lever arm with two masses
  • · Replies 2 ·
Replies
2
Views
2K
Can we find the frequency of a rod pendulum by just using F=ma?
  • · Replies 7 ·
Replies
7
Views
2K
Question about Normal Force and Torque
  • · Replies 5 ·
Replies
5
Views
3K
Torque v. Time Graph -- Find angular velocity
  • · Replies 4 ·
Replies
4
Views
14K
What Is the Required Thrust Force to Launch a 590 kg Rocket?
  • · Replies 10 ·
Replies
10
Views
9K