Calculating Distance Covered and Displacement

Distance Covered:
- The distance covered in one round of the circular track can be calculated using the formula: circumference = π x diameter.
- Given that the diameter is 40 meters, the circumference would be π x 40 = 40π meters.
- Therefore, the distance covered in one round of the track is 40π meters.
- To calculate the distance covered in 30 seconds, we need to find out how many rounds the athlete completes in 30 seconds.
- In 20 seconds, the athlete completes one round, so in 30 seconds, the athlete would complete 1.5 rounds.
- Therefore, the total distance covered in 30 seconds would be 1.5 x 40π = 60π meters.

Displacement:
- Displacement is the shortest distance between the initial and final positions of the athlete.
- In this case, as the athlete completes 1.5 rounds, the final position would be on the track itself but not at the starting point.
- The displacement can be calculated using the formula: displacement = 2r x sin(θ/2), where r is the radius of the track and θ is the angle subtended at the center of the circle.
- The radius of the track is half the diameter, so it is 20 meters.
- The angle subtended at the center for 1.5 rounds is 3π radians.
- Plugging in the values, we get displacement = 2 x 20 x sin(3π/2) = 40 meters.
Therefore, at the end of 30 seconds, the athlete covers a total distance of 60π meters and has a displacement of 40 meters.