# physics

posted by .

A runner circles a track of radius 50 m in 50 s moving at a constant rate. If the runner was initially moving north, what has been the runner's average acceleration when halfway around the track?

• physics -

First get the speed, which is constant.
It is 2 pi*50/50 = 6.28 m/s

The DIRECTION of velocity changes 180 degrees in the time it take to go half way around the track, 25 s. The velcoity changes by 12.56 m/s, from 6.28 to -6.28.

The AVERAGE acceleration is the change in the velocity vector divided by the time, which is
a(av) = 2*6.28/25 = 0.502 m/s^2

• physics -

The value of the acceleration scalar is always V^2/R = 0.789 m/s^2, but its direction is constantly changing. I don't believe that is what they area after.

## Similar Questions

1. ### Physics

An athlete starts at point and runs at a constant speed of 5.40 around a round track 250 in diameter Find the component of this runner's average velocity between points A and B. Find the component of this runner's average velocity …
2. ### physics

a runner run halfway around a circular track whose radius is 60 meters in 45 secs what is the average velocity?
3. ### Physics

A runner completes an 850m race with two laps of the 425m track in the x-y plane centered at the origin in 1 mins, 50.6s . A runner rounds the track counterclockwise starting at the point (67.6 , 0). Find the runner's average velocity …
4. ### Physics

At an instant, Runner 'A' runs at 6m/s with an acceleration of 2m/s^2. Runner 'B' runs at 5m/s with an acceleration of 4m/s^2, and the former (Runner A) is 2 metres ahead of the latter (runner B). How long does it take for Runner B …
5. ### physics

1.Moving with uniform acceleration a body covers 150m during 10sec so thet it covers 24m during the 10th sec .What is the initial velocity and the acceleration of the body. 2.A runner travels 1.5 laps around a circular track of 50sec …
6. ### physics

A runner covers one lap of a circular track 40.0 m in diameter in 62.5 s. Suppose initially the runner starts by going in the north direction. Assume the speed is constant for the first half-lap and then constant for the 2nd half-lap. …
7. ### physics

Suppose runner A starts at the 0 degree mark on a circular track (circumference = 400m). And let runner B start at the 180 degree mark. If runner A starts running counter clockwise with acceleration 2m/s^2, and runner B runs clockwise …
8. ### physics

Runner A is running at a constant rate of 2.3 m/s when he passes RUmmer B who is stationary. Runner A continues running at a constant pace, and Runner B begins to run 4 seconds after Runner A just passes him. If Runner B is accelerating …
9. ### Physics

Runner A is running at a constant rate of 2.3 m/s when he passes runner B who is stationary. Runner A continues running at a constant pace, and Runner B begins to run 4 seconds after Runner A just passes him. If Runner B is accelerating …
10. ### physics

A runner is moving at a constant speed of 8.00 m/s around a circular track. If the distance from the runner to the center of the track is 28.2 m, what is the centripetal acceleration of the runner?

More Similar Questions