> College of Science > Physics Dept > Tatsu Takeuchi > Special Relativity > Practice Problems > Problem 5
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### The Hare and the Tortoise 3

The hare and the tortoise decide to have another race. This time, they start out from opposite directions the same distance away from the finish line, as shown in the figure, and race toward each other. In the frame of the referee, which is at rest relative to the ground, the two animals cross their respective starting lines at the same time and then cross the finish line at the same time from opposite directions. The referee declares the race a tie. Assume that both animals were moving at constant velocities before, during, and after the race. Answer the following questions:

1. At which space-time point, labeled A through I, does the tortoise cross its starting line?
2. In the frame of the tortoise, at which space-time point is the hare when the tortoise crosses its starting line?
3. At which space-time point does the hare see the tortoise start?
4. Do both animals agree with the referee that they started at the same time? If not, explain in what chronological order the animals start in each animal's frame. Refer to the space-time diagram in your explanation.
5. Do both animals agree with the referee that they finished at the same time? If not, explain in what chronological order the animals start in each animal's frame. Refer to the space-time diagram in your explanation.