1
$\begingroup$

Newton's first law is interpreted as: A body remains in the state of rest or uniform motion in a straight line unless and until an external force acts on it. I was told by my teacher that a body has only two natural states i.e. state of rest and state of uniform motion. If viewed from the same frame of reference what caused the uniform motion in the first place as opposed to a body in rest?

$\endgroup$

2 Answers 2

5
$\begingroup$

Newton's first law describes how bodies move in the absence of an external force. As soon as external forces are involved, you have to turn to his second law $F=ma$, which describes how a force $F$ can cause an acceleration (and therefore an increase in velocity) of a certain object.

Hope that helps!

$\endgroup$
1
$\begingroup$

The body can be set into motion by some external force, like a push for example. Newton's first law then holds once that external force is no longer applied.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.