A particle with a charge of -4.50x 10^-10 C and a mass of 6.6x 10^-18 kg is placed between two oppositely charged parallel plates with a voltage of 9.00x 10^5 V. The particle is injected at the negative plate with an initial speed of zero. What is the final speed of the particle just before it strikes the positive plate?

ΔKE = W (of electric field)

0 – mv^2/2 = qU
v=sqrt (2qU/m)

To find the final speed of the particle just before it strikes the positive plate, we can use the principles of electrostatics and motion equations.

First, let's determine the electric field between the two plates. The electric field (E) can be calculated using the equation:

E = V / d

Where V is the voltage between the plates and d is the distance between the plates.

Given:
V = 9.00x 10^5 V (voltage between the plates)
d = ? (distance between the plates)

Unfortunately, the distance between the plates is not provided in the given information. We need more information to determine the final speed of the particle.

Could you please provide the distance between the two plates?