## Force, Acceleration, mass and time

If I have a 1kg object moving on a straight path at 10m/s, I have to apply a force of 10N in the opposite direction to its trajectory to stop it completely, right? Does that mean I have to apply a force of 10N for one second to stop it completely? In that case, would a force of 10N for half a second only decelerate it to 5m/s and a force of 20N take half a second to stop it? And if that is the case wouldn't a wall have to apply a force much greater than 10m/s to stop the object, as it does, in fractions of a second?

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 Quote by V0ODO0CH1LD If I have a 1kg object moving on a straight path at 10m/s, I have to apply a force of 10N in the opposite direction to its trajectory to stop it completely, right?
Not necessarily. It all depends on how quickly you want to stop it.
 Does that mean I have to apply a force of 10N for one second to stop it completely?
If you do apply such a force for such a time, then you will stop it completely.
 In that case, would a force of 10N for half a second only decelerate it to 5m/s and a force of 20N take half a second to stop it?
Exactly.
 And if that is the case wouldn't a wall have to apply a force much greater than 10m/s to stop the object, as it does, in fractions of a second?
Yes.
 Thank you! That really helped!

## Force, Acceleration, mass and time

 Quote by V0ODO0CH1LD And if that is the case wouldn't a wall have to apply a force much greater than 10 N (you used the wrong units) to stop the object, as it does, in fractions of a second?
Yes, the forces when hitting a wall can easily be orders of magnitude greater than "regular" forces, which is exactly why you don't want to run your car into a wall.

 Tags acceleration, force, mass, time