A potential difference is applied between two horizontal metal plates that are a distance of 6.0 mm apart in a vacuum, as shown in Fig. 7.1. [Figure 7.1] The top plate has a potential of –450V and the bottom plate is earthed. Assume that there is a uniform electric field produced between the plates. A radioactive source emits a β⁻ particle that travels through a hole in the bottom plate and along a vertical path until it reaches the top plate.

1. (a)(i)Determine the magnitude and the direction of the electric force acting on the β⁻ particle as it moves between the plates.[4]
2. (a)(ii)Calculate the work done by the electric field on the β⁻ particle for its movement from the bottom plate to the top plate.[2]
3. (b)The β⁻ particle is emitted from the source with a kinetic energy of 3.4 x 10⁻¹⁶ J. Calculate the speed at which the β⁻ particle is emitted.[2]
4. (c)(i)Complete the equation below to represent the decay of a neutron. ⁰₁n → ⁻₁⁰β + ______ + ______[2]
5. (c)(ii) 1.neutrons[1]
6. (c)(ii) 2.β⁻ particles.[1]

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