- #1
Amad27
- 412
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Homework-like problem originally posted in a non-homework forum
Hello,
Before anyone thinks this is a coursework question, it is not. It is a challenge problem, which I found online, and seems worth discussing.
(Question) In a 400-m relay race the anchorman (the person who runs the last 100 m) for team A can run 100 m in 9.8 s. His rival, the anchorman for team B, can cover 100 m in 10.1 s. What is the largest lead the team B runner can have when the team A runner starts the final leg of the race, in order that the team A runner not lose the race?
The answer is 3.0m, how?
Calculus please (wherever applicable).
First we have team A, which we can denote by [itex]A[/itex] <--- The anchorman
Team B can be denoted by [itex]B[/itex] <-- The anchorman
Since [itex]v_a(t) = 10.204 m/s[/itex]
[itex]v_b(t) = 9.9009 m/s[/itex]
[itex]x_a(t) = 10.204t[/itex]
[itex]x_b(t) = 9.9009t[/itex]
But [itex]x_a(t) > x_b(t)[/itex] for all real [itex]t[/itex] so, runner B cant overtake runner A?
Before anyone thinks this is a coursework question, it is not. It is a challenge problem, which I found online, and seems worth discussing.
(Question) In a 400-m relay race the anchorman (the person who runs the last 100 m) for team A can run 100 m in 9.8 s. His rival, the anchorman for team B, can cover 100 m in 10.1 s. What is the largest lead the team B runner can have when the team A runner starts the final leg of the race, in order that the team A runner not lose the race?
The answer is 3.0m, how?
Calculus please (wherever applicable).
First we have team A, which we can denote by [itex]A[/itex] <--- The anchorman
Team B can be denoted by [itex]B[/itex] <-- The anchorman
Since [itex]v_a(t) = 10.204 m/s[/itex]
[itex]v_b(t) = 9.9009 m/s[/itex]
[itex]x_a(t) = 10.204t[/itex]
[itex]x_b(t) = 9.9009t[/itex]
But [itex]x_a(t) > x_b(t)[/itex] for all real [itex]t[/itex] so, runner B cant overtake runner A?