Thrust separate from acceleration?

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SUMMARY

The discussion focuses on the physics of a model rocket's launch, specifically the relationship between thrust and acceleration. The thrust force (F) generated by the rocket's engine is constant during the burn time (t) and is responsible for the upward acceleration. The equation of motion derived is y(t) = 0.5Ft², indicating that height is a function of thrust and time. It is clarified that thrust is not equivalent to acceleration; rather, acceleration is the result of the net force acting on the rocket, which includes gravitational force (mg) acting downward.

PREREQUISITES
  • Understanding of Newton's second law (f=ma)
  • Basic knowledge of kinematics in physics
  • Familiarity with forces acting on objects (thrust vs. gravity)
  • Concept of net force and its role in acceleration
NEXT STEPS
  • Study the derivation of kinematic equations for uniformly accelerated motion
  • Learn about the effects of gravity on projectile motion
  • Explore the concept of net force and its calculation in various scenarios
  • Investigate real-world applications of thrust in rocketry and aerospace engineering
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Students studying physics, educators teaching mechanics, and enthusiasts interested in rocketry and motion dynamics.

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Homework Statement


A model rocket blasts off vertically from rest at time t=0 being pushed by an engine that produces a constant thrust force F up. The engine blasts away for t seconds and then stops. Find the height y and vertical velocity that the rocket has reached by the end of the blast time t.


Homework Equations


f=ma


The Attempt at a Solution


a = F
y(t) = .5Ft^2

Is acceleration really the same as the thrust, or is acceleration the thrust - the effect of gravity?
 
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Thrust is the force pushing the rocket up. mg is the gravitational force pulling the rocket down. Both forces are acting on the rocket while the engine is on. The 'F' in F=ma is the total force. So no, F is not the same as acceleration. You'll need to express the answer in terms of the mass 'm' of the rocket.
 

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