An entirely separate mass from the rocket is required for a reaction to the rocket's action to be produced.
And just what action is the rocket producing?
A fellow called Newton described it quite well hundreds of years ago; here are the details:
Yes, because that is a comprehensive list of every possible action/reaction pair, right?
It's funny how Papa just ignores the rest of his "authority" for his action/reaction pairs. Here is a bit:
Examples of Interaction Force Pairs
Consider the motion of a car on the way to school. A car is equipped with wheels that spin. As the wheels spin, they grip the road and push the road backwards. Since forces result from mutual interactions, the road must also be pushing the wheels forward. The size of the force on the road equals the size of the force on the wheels (or car); the direction of the force on the road (backwards) is opposite the direction of the force on the wheels (forwards). For every action, there is an equal (in size) and opposite (in direction) reaction. Action-reaction force pairs make it possible for cars to move along a roadway surface.
from Physics Classroom - Home, Newton's Laws - Lesson 4 - Newton's Third Law of Motion
That's the last bit of Papa's "borrowed quote", though most people would have acknowledged the source!
And then the bit he quite carefully omitted:
2. For years, space travel was believed to be impossible because there was nothing that rockets could push off of in space in order to provide the propulsion necessary to accelerate. This inability of a rocket to provide propulsion is because ...
a. ... space is void of air so the rockets have nothing to push off of.
b. ... gravity is absent in space.
c. ... space is void of air and so there is no air resistance in space.
d. ... nonsense! Rockets do accelerate in space and have been able to do so for a long time.
See Answer
Then the answer: Check your understanding answer
Answer: D
It is a common misconception that rockets are unable to accelerate in space. The fact is that rockets do accelerate. There is indeed nothing for rockets to push off of in space - at least nothing which is external to the rocket. But that's no problem for rockets. Rockets are able to accelerate due to the fact that they burn fuel and push the exhaust gases in a direction opposite the direction which they wish to accelerate.
So we have 2 objects! The rocket AND the exhaust gases! 1 + 1 = 2!
And he NEVER has anything to say about this little omission?
To be fair I think his source omitted it. I think there is a few sites using the same source material they just use all or some of it.
http://www.physicsclassroom.com/class/newtlaws/Lesson-4/Newton-s-Third-LawTo his discredit he seemed to have avoided any source that mentioned rockets.
I think his copy and paste is from here:
http://www.mwit.ac.th/~physicslab/applet_04/physics_classroom/Class/newtlaws/u2l4a.htmlIf it is he missed this, which is easy if you do not scroll down to the questions:
2. Rockets are unable to accelerate in space because ...
A. there is no air in space for the rockets to push off of.
B. there is no gravity is in space.
C. there is no air resistance in space.
D. ... nonsense! Rockets do accelerate in space.
Papa would answer A, the source says the answer is D and supplies a short explanation.
Poll