# Newtons 1st law

kath102245

## Main Question or Discussion Point

Can anyone out there give me some examples of newtons 1st law?

~Kathleen

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russ_watters
Mentor
A rocket at takeoff.

Sure, Newton's first law says that an object in motion will stay in motion in a straight line (or an object at rest will stay at rest) unless acted upon an outside force.

So for the rest part, go outside and find a rock, watch the rock...just kidding, but pick up the rock and you are the outside force.

More seriously though, take the rock and tie some string to it, go away from anything you don't want broken and swing the rock around in an arc, feel the rock pull at your hand? that's you supplying a force so that the rock travels in a curve instead of a straight line...now watch the rock carefully becuase you're gonna release it and watch it fly, not out away from your hand but perpendicular to the curve where you let it go, and it goes in a straight line.

everything that isn't accelerating is an example of newton's first law. for any object that is not accelerating (this includes turning or spinning), all the forces on it must be equal (i.e. the net force on the object is 0). such objects will either be stationary or moving at constant velocity.

khalid_kacst

Originally posted by Zimm
More seriously though, take the rock and tie some string to it, go away from anything you don't want broken and swing the rock around in an arc, feel the rock pull at your hand? that's you supplying a force so that the rock travels in a curve instead of a straight line...now watch the rock carefully becuase you're gonna release it and watch it fly, not out away from your hand but perpendicular to the curve where you let it go, and it goes in a straight line.

COULD ANYONE EXPLAIN THIS A LITTLE BIT EASIER? CAUSE I'M GOING TO USE THIS EXAMPLE IN MY PROJECT.

THNX

Jer
If you pick up a rock and throw it in the air, it will come back down to earth. It does this because there is an unbalanced force (gravity, frictional forces (from air resistance), etc.) acting on it.