Q-4.10

A positron (charge te, mass equal to the electron mass) is moving at 1.2 x 10' m/s in the positive direction of an x axis when, at x = 0, it encounters an electric field directed along the x axis. The electric potential V associated with the field is given in the figure. The scale of the vertical axis is set by Vs = 500.0 V. (a) Does the positron emerge from the field at x = 0 (which means its motion is reversed) or at x = 0.50 m (which means its motion is not reversed)? (b) What is its speed when it emerges? V (V) x (cm) 20 50 (a) Number Units (b) Number Units