Define drift velocity of free electron . If relaxation time is r then write a vector relation b etween drift velocity and electric field.

Answer

2

Explanation

Using relative motion, the time of collision `t = (h)/(20 + 0) = 1s`
By conservation of momentum for collision `3(10) + 1 (-10) = 4 (V) rArr V = 5 m//s`
`KE = (1)/(2) (4) (5)^(2) = 50J`