00:01
All right, so let's say we have several circumstances where a car is accelerating.
00:04
For part a, we're told the initial velocity is zero, and the final velocity is 42 feet per second, and the time interval this occurs at is 4 .5 seconds.
00:17
So the acceleration is going to be the final velocity minus the initial velocity over this time interval.
00:22
So 42 over 4 .5.
00:24
This is 9 .33 feet per second squared.
00:30
Part b, we want to do the same thing but with a different interval.
00:36
So now delta t is three and a half seconds.
00:41
And our initial velocity is 42.
00:44
And our final velocity is 84 feet per second.
00:50
So now the acceleration, it's still 42 over 3 .5.
00:55
So this is 12 feet per second squared.
00:58
And in case c, it slows to a final velocity of 63 feet per second, given an initial velocity, presumably of 84 feet per second, and the time interval is 2 .5 seconds...