In: Physics
The bacterium Escherichia coli (or E. coli) is a single-celled organism that lives in the gut of healthy humans and animals. When grown in a uniform medium rich in salts and amino acids, these bacteria swim along zig-zag paths at a constant speed of 20 um/s. The figure shows the trajectory of an E. coli as it moves from point A to point E. Each segment of the motion can be identified by two letters, such as segment BC.
What is the magnitude of the bacterium's average velocity for the entire trip?
a )IN 1st segment
Vx = 20 μm/s cos(tan inverse (1/5)) = 19.61μm/s
V y = 3.922um/s
In 2nd Segment
Vx=0
Vy = 20um/s
Segment 3 : Vx = 20 μm/s cos(tan inverse (1/4)) = 19.4μm/s
Vy = 4.85um/s
segment 4 : Vx = -20 μm/s cos(45) = -14.14μm/s
V y = -14.14um/s
b)Distance travelled = 172.93μm
displement = 44.72m
c) average velocity = displement/time = 44.72m/8.64sec =
5.17μm/sec
Average speed = distance /time = 172.93/8.64 = 20μm/sec