Thursday, 21 February 2013

1.21 use the idea of momentum to explain safety features

force felt= change in momentum/time

If the time taken for momentum to change is increased, the overall force felt is decreased.
Crumple zones in cars increase the time it takes for the cars momentum to reach zero, meaning passengers feel less of the force. Air bags do the same thing; increasing the time till momentum of a body reaches zero reduces the force felt.

To understand if you jump with you knees locked you can feel more of the force. If when you hit the ground you bend your knees the landing is softer as you feel less force. This happens because when you finish by bending your knees you take more time to reach zero momentum therefore reducing the force felt.

11 comments:

  1. why are your spec points different to mine?

    ReplyDelete
    Replies
    1. It could be because you are on a different course? But its probably because this is for the 2013 course.

      Delete
    2. it's 2016 now and the points are pretty much the same

      Delete
  2. Hey, this is very useful but think you should say 'resultant force' rather than 'force felt'

    ReplyDelete
    Replies
    1. who is this deejsify mug, questioning one of my main sources of revision

      Delete
    2. This comment has been removed by the author.

      Delete
  3. Our physics teacher spent 30 minutes explaining so many different examples in loads of detail for this sort of moment stuff.

    Your site is so much simpler and easy to understand, thank you so much!!!

    ReplyDelete
  4. this actually simplified it so much, ur an actual legend u kno that

    ReplyDelete
  5. if i revise completely from these notes will i get an A*.

    ReplyDelete