Problems. Electrical phenomena in nature
Answers are for parents and teachers.
1
A force of 3.2·10⁻¹⁵ N acts on a body at E = 800 N/C. How many excess electrons does it have?
25
2
A droplet with a charge of 5 nC hangs in a 6000 N/C field. What is its mass in mg? (g = 10 m/s²)
3
3
Thunder is heard 9 s after a flash. How many metres away is it?
3060
4
Why is it dangerous to shelter from lightning under a lone tree in the open?
Lightning strikes tall conducting objects first; the charge can pass from the tree to a person.
5
Find E at 3 cm from a 5 nC point charge in a liquid with ε = 3.
E = 9·10⁹ · 5·10⁻⁹ : (3 · 0.03²) = 45 : 2.7·10⁻³ ≈ 1.7·10⁴ N/C.