00:01
A rocket rises vertically with an acceleration of 3 .2 meters per second squared until it runs out of fuel at an altitude of y0, which is, or let's label this altitude as y1, that is 725 meters.
00:23
First, we have to find velocity of the rocket when it runs out of fuel.
00:29
Let's label this velocity as v1, so let's illustrate it.
00:36
This is the y -axis which is upwards, that is a 0, and this kite is y -1, where it has a velocity of v1.
00:48
And the acceleration is g downwards, that constantly acts here in the system.
00:57
This velocity v1 equals to a, actually it can be found as following.
01:08
Y1 equals to v1 squared minus 0 squared divided by 2a therefore, v1 equals to square root of 2 y1 times a that is square root of times 725 meters times 3 .2 meters per second squared let's calculate it that is 68 .1 meters per second.
02:16
Now let's answer question b.
02:19
Here we have to calculate how long it will take to each this point, so we have to calculate this t1.
02:25
And this time t1 equals to v1 divided by a1, which is 68 .1 meters per second divided by 3 .2 meters per second squared.
02:44
That is 21 .3 seconds.
02:51
Answer question c here we have to calculate maximum altitude so maximum altitude equals to y1 plus v1 squared divided by 2g which is 725 meters plus 68 .1 meters per second squared also 61 .2 meters per second squared squared squared divided by 2g which is 2 9 .8 meters per second squared that is 960 meters now let's answer question d here we have to calculate total time of the flight also time to which is needed to reach the maximum altitude and this time equals to t1 plus time needed when the rocket deaccelerates from v1 to 0 meters per second.
04:34
And this is t1 plus v1 divided by g...
