Two identical particles, each having a charge of `2.0xx10^(-4) C` and then released. What would be the speeds of the particles when the separtion becomes large?

Answer

`600 ms^(-1)`

Explanation

Here, `q = 2xx10^(-4)C, m = 10 g = 10^(-2) kg`,
`r = 10 cm = 0.1m`.
Let v , speed of each particle at infinite sepraration P.E. of two particles at the separationo of 10 cm. = K.E. of two particles at infinite separation
`(1)/(4pi in_(0)) (q_(1) q_(2))/(r ) = (1)/(2) mv^(2) + (1)/(2) mv^(2)`
`v^(2) = (1)/(4pi in_(0)) (q_(1) q_(2))/(r m) = (9xx10^(9)xx2xx10^(-4)xx2xx10^(-4))/(0.1xx10^(-2))`
`= 36xx10^(4)`
`v = 600 ms^(-1)`