An electron moves in a straight line through a vacuum at a constant speed of $1.5 \times 10^{7}\,\text{m s}^{-1}$. It enters a uniform electric field at point A, as shown in Fig. 5.1. It keeps travelling in the same direction until the electric field brings it to rest at point B. The distance AB is $2.0\,\text{cm}$.
(a)[1]
State the direction in which the electric field acts.
(b)[2]
Calculate the magnitude of the electron’s deceleration in the field.
(c)[3]
Calculate the electric field strength.
(d)[1]
At time $t = 0$, the electron is at point A. On Fig. 5.2, sketch how the velocity $v$ changes with time $t$ from A until it reaches point B. Numerical values of $v$ and $t$ do not need to be shown.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Direction given as to the right / from A to B / the same as the electron velocity” …