Answer: 0.642mm
Explanation: F= force = 5.2×10^-16 N,
v = velocity of electron = 1.2×10^7 m/s,
m = mass of electron = 9.11×10^-31 kg.
We will assume the motion of the object to be of a constant acceleration, hence newton's laws of motion is applicable.
Recall that f = ma.
Where a = acceleration
This acceleration of vertical because it occurred when the object deflected.
5.2×10^-16 = 9.11×10^-31 (ay)
ay = 5.2×10^-16 / 9.11×10^-31
ay = 5.71×10^14 m/s²
For the horizontal motion, x = vt
Where x = horizontal distance = 0.019m and v is the velocity = 1.2×10^7 m/s,
By substituting the parameters, we have that
0.019 = 1.27×10^7 × t
t = 0.019 / 1.27 × 10^7
t = 1.5×10^-9 s
The vertical distance (y) is gotten by using the formulae below
y = ut + at²/2
but u = 0
y = at²/2
y = 5.71×10^14 × (1.5×10^-9)²/2
y = 0.00128475/2
y = 0.000642m = 0.642mm