00:01
Hello students, in this question it is mentioned that a bicycle racer sprints at the end of a race to clinch a victory.
00:06
So the racer has an initial velocity v i is equal to 11 .5 m per second and he accelerates at a rate of 0 .500 m per second square.
00:19
Now the time t is also given in the question as 7 seconds.
00:23
So in the a part of the question we have to find what is his final velocity.
00:27
So v final is equal to v initial plus 80.
00:35
That is we have used equation v is equal to u plus 80.
00:40
Now substituting the values we get vf is equal to 11 .5 into acceleration that is 0 .5 into t, 7 seconds.
00:50
We get the final velocity is equal to final velocity vf is equal to 15 .0 m per second.
01:06
So this is the final velocity of the racer.
01:09
Now in the b part of the question the racer continues at this velocity to finish the line.
01:13
If he was 300 meters from the finish line when he started to accelerate how much time did he save? so the average the racer started accelerating when he was 300 meters from finish line and his final velocity vf was 15 m per second.
01:46
So using the equation v final v final is equal to v initial plus 80.
01:56
We get final velocity that is 15 is equal to 11 .5 plus 80 that is 0 .5 into time t.
02:10
Calculating we get time t is equal to 7 seconds...