Mechanics > Kinematics >  2-D > Circular Motion DCS# 1D52.45

ROTATING CORN

rotating corn

APPARATUS
turntable 101-02-D2
huge inverted dog bowl or 11" tupperware tub 101-02-D2
potting soil 101-02-D2
corn seeds 101-02-D2
plant light 101-15-C


DESCRIPTION
Show how corn grows in a rotating reference frame.
 
NOTES
 
Use 78 rpm.

Angle from vertical is given by:

     θ   = tan-1 (Fc/Fg

 = v2/rg
   = ω 2r/g

 = (2π *78 rev / 60 s)2 (0.15 m) / (9.8 m/s2)

 = 1.0
 
 = 45°

Plant corn about two weeks before demo is to be shown.  Or let the seeds germinate in wet paper towels before planting.  Plant in a ring about 15 cm in radius.  Position the plant light to the side rather than directly above the pot so that the effect cannot be attributed to the light-seeking behavior of the plants.  See detailed instructions in corn.docx.

This is also available as a corridor display:

corn display