Which law of motion accounts for seatbelts

  • Thread starter Thread starter jakeginobi
  • Start date Start date
  • Tags Tags
    Law Motion
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
5 replies · 2K views
jakeginobi
1. The problem statement, all variables and
given/known data

What would the best choice be:Newton's Law 1 or 2 or 3. Wearing a seatbelt and when it stops.

Homework Equations


N/A

The Attempt at a Solution


I thought the best choice would be 3 because for every action there's a reaction. I don't know any responses that fit to Newton's Law 1. I don't think it's Law 1 because objects tend to stay in motion/rest unless acted by external force, and there was an unbalanced force that caused change - or does it also imply that if an unbalance force is exerted it fits Newton's Law 1? The seat belt causes an external force and Law 1 states that the net force would be 0

One more question why would this be Newton's 1st law?
"a frog leaping upward off his lily pad is pulled downward by gravity and lands on another lily pad instead of contiuing on in a straight line"
I'm confused about if an object were to stop would it be considered Newton's 1st law
 
Last edited by a moderator:
Physics news on Phys.org
First answer this: why do you wear a seatbelt?
 
  • Like
Likes   Reactions: CWatters
jakeginobi said:
1. The problem statement, all variables and
given/known data

What would the best choice be:Newton's Law 1 or 2 or 3. Wearing a seatbelt and when it stops.

Homework Equations


N/A

The Attempt at a Solution


I thought the best choice would be 3 because for every action there's a reaction. I don't know any responses that fit to Newton's Law 1. I don't think it's Law 1 because objects tend to stay in motion/rest unless acted by external force, and there was an unbalanced force that caused change - or does it also imply that if an unbalance force is exerted it fits Newton's Law 1? The seat belt causes an external force and Law 1 states that the net force would be 0

One more question why would this be Newton's 1st law?
"a frog leaping upward off his lily pad is pulled downward by gravity and lands on another lily pad instead of contiuing on in a straight line"
I'm confused about if an object were to stop would it be considered Newton's 1st law
In your analysis, I don't see any consideration of Newton's 2nd law. Is your body decelerating? Is the seat belt exerting a force on your body? Have you drawn a free body diagram of your body during the time the seat belt force is acting on it?
 
The seat belt exerts a force to stop the person from going forward.

If there is an acceleration/deceleration does it mean that it isn't Newton's 1st law?
 
jakeginobi said:
The seat belt exerts a force to stop the person from going forward.

So, you get into your car, you fasten your seat belt and the seat belt "stops you going forward"? Really? Is that why you wear a seat belt? It's not why I wear one!
 
jakeginobi said:
The seat belt exerts a force to stop the person from going forward.

What's wrong with going forward?
 
  • Like
Likes   Reactions: billy_joule and SammyS