An electron is a subatomic particle (m = 9.11 10-31 kg) that is subject to electric forces. An electron moving in the +x direction accelerates from an initial velocity of +5.16 105 m/s to a final velocity of +2.23 106 m/s while traveling a distance of 0.037 m. The electron's acceleration is due to two electric forces parallel to the x axis: 1 = +6.89 10-17 N, and 2, which points in the -x direction. Find the magnitudes of the net force acting on the electron and the electric force 2.

Question

An electron is a subatomic particle (m = 9.11  10-31 kg) that is subject to electric forces. An electron moving in the +x direction accelerates from an initial velocity of +5.16  105 m/s to a final velocity of +2.23  106 m/s while traveling a distance of 0.037 m. The electron's acceleration is due to two electric forces parallel to the x axis: 1 = +6.89  10-17 N, and 2, which points in the -x direction. Find the magnitudes of the net force acting on the electron and the electric force 2.

Elena · Answer

a=(v²-v₀²)/2•s = {(2.23•10⁶)²-(5.16•10⁵)}/2•0.037 =6.36•10^13 m/s²
F(net) =ma= 9.1•10^-31•6.36•10^13=5.78•10^-17 N.
ma=F1-F2.
F2=F1-ma=6.89•10^-17-5.78•10^-17 = 1.11•10^-17 N.(in –x-direction)