Cracking the SAT Physics Subject Test

(Marvins-Underground-K-12) #1

4. Using F = ∆p / ∆t, we find that



  1. In this case


Time
Seconds are represented
in questions as s. If you
see a quantity that refers
to time labeled with ms,
it is using milliseconds.
Because impact happens
so quickly, a smaller
unit of time is
necessary.

This force is equivalent to about 27 tons(!), more than enough
force to break bones and cause fatal brain damage. Notice how
crucial the impact time is: Increasing the slowing-down time
reduces the acceleration and the force, ideally enough to
prevent injury. This is the purpose of safety devices such as air
bags in cars.


  1. A small block is struck by a force F whose strength varies with
    time according to the following graph:

Free download pdf