A = ΔEk
A = q*U
ΔEk = Ek2 - Ek1 = (m*v2^2)/2 - (m*v1^2)/2 = m*(v2^2-v1^2)/2
q*U = m*(v2^2-v1^2)/2
q = m*(v2^2-v1^2)/(2*U) = 4*10^(-19)*((3*10^7)^2-(10^7)^2)/(2*2*10^4) = 8*10^(-9) (Кл) = 8(нКл)
Ответ: q = 8 нКл
A = ΔEk
A = q*U
ΔEk = Ek2 - Ek1 = (m*v2^2)/2 - (m*v1^2)/2 = m*(v2^2-v1^2)/2
q*U = m*(v2^2-v1^2)/2
q = m*(v2^2-v1^2)/(2*U) = 4*10^(-19)*((3*10^7)^2-(10^7)^2)/(2*2*10^4) = 8*10^(-9) (Кл) = 8(нКл)
Ответ: q = 8 нКл