Acceleration and relativity question

[asdf1]

In this question, "Find the acceleration of a particle of mass m and velocity v when it is acted upon by the constant force F, where F is parallel to v."
Why do you need to consider relativity?

 

[quasar987]

This question is kind of equivalent to "find Newton's second law" taking relativity under consideration.

hint: F = dp/dt

 

[HallsofIvy]

In this question, "Find the acceleration of a particle of mass m and velocity v when it is acted upon by the constant force F, where F is parallel to v."
Why do you need to consider relativity?

Who told you you needed to consider relativity? Relativity only comes into play when the speed is a large fraction of the speed of light. There doesn't appear to be anything in the problem you quoted to indicate that. Was there more to the problem? It might well be that the answer to the question "Why do you need to consider relativity?" is "Because the problem (or your teacher) said to!"

 

[asdf1]

well, the problem was an example in a modern physics book I'm looking at,
but my first reaction was the same as quasar987~