a Calculate its kinetic energy in joules at 580 of the speed
(a) Calculate its kinetic energy in joules at 5.80% of the speed of light.
J
(b) What is this in electron volts?
eV
(c) What voltage would be needed to obtain this energy?
V
Solution
a)
at v = 0.058 c
kinetic energy = m0 * c^2/sqrt(1 - (v/c)^2) - m0 * c^2
kinetic energy = 6.64 *10^-27 * (3 *10^8)^2/sqrt(1 - 0.058^2) - 6.64 *10^-27 * (3 *10^8)^2
kinetic energy = 1.01 *10^-12 J
the kinetic energy of Helium atom is 1.01 *10^-12 J
b)
converting to eV
kientic energy = 1.01 *10^-12/(1.602 *10^-19)
kientic energy = 6.304 *10^6 eV
c)
let the voltage nedeed is V
2 * e * V = kinetic energy
2 * V * e = 6.304 *10^6 eV
V = 3.15 *10^6 V
the potential needed is 3.15 *10^6 V
