Solution:
[Step 1]: Dipole moment
[Step 2]:
[Step 3]:
[Step 4]:
[Step 5]:
[Step 6]: For pure rolling
A disc having uniform surface charge density in upper half and in lower half is placed on a rough horizontal surface as shown in figure. A uniform electric field is set up as shown. If mass of disc is M and its radius is R, as well sufficient friction is present to prevent slipping, the acceleration of disc is
[Step 1]: Dipole moment
[Step 2]:
[Step 3]:
[Step 4]:
[Step 5]:
[Step 6]: For pure rolling