A very large horizontal non-conducting plane sheet carries a uniform surface charge…
PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
A very large horizontal non-conducting plane sheet carries a uniform surface charge density σ=8.0×10−8C m−2. A tiny oil drop of mass 2.0×10−7kg and charge +1.6×10−19C is released from rest at a height of 5.0m above the sheet in air. Neglect air resistance and take g=9.8m s−2.
(i) Determine the magnitude and direction of the electric field produced by the sheet.
(ii) Find the magnitude and direction of the net force acting on the oil drop just after it is released.
(iii) Calculate the acceleration of the drop and hence determine the time it takes to reach the sheet.