The acceleration due
to the electric field E is eEm=1.6×10−19×20009.1×10−31=3.2×10159.1 downward and is constant.
Hence, the motion is
equivalent to a projectile motion.
T=2usinθa
range R=u2sin2θa=(6×106)2sin(2×450)3.2×10159.1=0.1m=10cm
∴ the electron will
strike the lower plate at the edge.
Max height reached: H=u2sin2θ2a=(6×106)2×(1√2)22×3.2×10159.1=0.025m=2.5cm
Since max height reached by
electron is less than the separation between the plates, it will not
strike the upper plate.
Hence it will touch the lower plate at the edge.