Question

1. On July 17, 1969, while Apollo 11 was on its way to the Moon for the first Moon landing, The New York Times printed the following retraction of a 1920 editorial:

On Jan. 13, 1920, “Topics of The Times,” an editorial-page feature of The New York Times, dismissed the notion that a rocket could function in a vacuum and commented on the ideas of Robert H. Goddard, the rocket pioneer, as follows:

“That Professor Goddard, with his ‘chair’ in Clark College and the countenancing of the Smith- sonian Institution, does not know the relation of action to reaction, and of the need to have something better than a vacuum against which to react–to say that would be absurd. Of course he only seems to lack the knowledge ladled out daily in high schools.”

Further investigation and experimentation have confirmed the findings of Isaac Newton in the 17th century and it is now definitely established that a rocket can function in a vacuum as well as in an atmosphere. The Times regrets the error.

Using Newton’s 3rd law, explain the physics that the editorial writer apparently didn’t understand, namely why a rocket can work perfectly well in a vacuum.

Answer 1