Calculate the accelerating potential that must be applied on a proton beam to give it an effective wavelenth of 0.005 nm.

Explanation

(1) `lamda=(h)/(mv)=(6.626xx10^(-34))/(1.67xx10^(-27)xxv)" "therefore v=7.94xx10^(4)m*s^(-1)`
(2) If accelerating potential is V volts, then energy acquired by the proton=eV. This becomes the kinetic energy of the proton. Hence, `eV=(1)/(2)mv^(2)`
`V=(1)/(2)xx(1.67xx10^(-27)xx(7.94xx10^(4))^(2))/(1.6xx10^(-19))" "therefore V=32.8v`