Answer:
(a) The acceleration lasts 9.642 seconds.
(b) The acceleration of the fireworks shell is 5.808 meters per square second.
Explanation:
Statement is incomplete. Complete description is presented below:
<em>A fireworks shell is accelerated from rest to a velocity of 56 meters per second over a distance of 0.270 meters. </em><em>(a)</em><em> How long (in seconds) did the acceleration last? </em><em>(b)</em><em> Calculate the acceleration.</em>
(b) Let suppose that the fireworks shell is accelerated uniformly. Given that initial (
) and final speed (
), measured in meters per second, and distance (
), measured in meters, are known, we calculate the acceleration (
), measured in meters per square second, by this kinematic expression:
(1)
If we know that
,
and
, then the acceleration is:


The acceleration of the fireworks shell is 5.808 meters per square second.
(a) Now we calculate the time associated with acceleration (
), measured in seconds, by means of this kinematic equation:

If we know that
,
and
, then time associated with acceleration is:


The acceleration lasts 9.642 seconds.