A tiny bird carrying a charge of dives vertically down towards a large positively charged metallic…
A tiny bird carrying a charge of $q = 8 \times 10^{-17}\text{ C}$ dives vertically down towards a large positively charged metallic plate (with surface charge density $\sigma = 4\cdot425 \times 10^{-12}\text{ C m}^{-2}$) as shown in Figure 3. How much work is done by the electrostatic force when the bird moves through a distance of $0\cdot5\text{ m}$ towards the plate?
Answer
Answer
AIWritten by AI (gemini) - it can contain mistakes.
$qE = mg \implies q\frac{\sigma}{2\epsilon_0} = mg \implies \sigma = \frac{2mg\epsilon_0}{q} = \frac{2 \times 50 \times 10^{-3} \times 9\cdot8 \times 8\cdot85 \times 10^{-12}}{8 \times 10^{-17}} = 10\cdot8 \times 10^4\text{ V m}^{-1}$
Final answer: 10.8e4 V/m
From ISC 2027 Specimen Physics Paper 1, question 2(ii).