Question
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?
Answers
drwls
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
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
drwls
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.