contestada

A runner covers one lap of a circular track 40.0m in diameter in 63.0s . For that lap, her average speed is 1.99 m/s.

For that lap, what is her average velocity?

If she covered the first half-lap in 28.8s , what was her average speed for that half-lap?

If she covered the first half-lap in 28.8s , what were her average velocity for that half-lap?

Respuesta :

Edufirst
1) Average velocity = displacement / time

Displacement = 0; because the runner ended in the same starting point.

Therefore, the average velocity is 0.

2) Average speed = distance covered / time

Distance covered = half-circumference of a 40.0 m diameter circle. = π*40m/2 = 20π m

Average speed = 20π m / 28.8 s = 2.18 m/s

3) Average velocity = displacement / time

displacement = diameter of the circle; because the runner is just in the point opposed by the diamter to the point where she started..

Average velocity = 40.0 m / 28.8 s = 1.39 m/s
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