State which property an object must have in order to experience a force when it is placed in a gravitational field.
State which property an object must have in order to experience a force when it is placed in an electric field.
A potential difference of $1.2 \times 10^{3}\,\text{V}$ is applied across a pair of horizontal metal plates in a vacuum, as illustrated in Fig. 3.1. The gap between the plates is $3.6\,\text{cm}$ and the electric field between them is uniform. A particle of mass $5.9 \times 10^{-6}\,\text{kg}$ and charge $-4.2 \times 10^{-9}\,\text{C}$ enters the field at point $X$ with a horizontal velocity of $0.75\,\text{m s}^{-1}$ along a line halfway between the two plates. The particle is deflected by the field and strikes the top plate at point $Y$. Calculate the magnitude of the electric force acting on the particle in the field.
By considering the resultant vertical force on the particle, show that its acceleration in the electric and gravitational fields is $14\,\text{m s}^{-2}$.
Determine the time taken for the particle to travel from $X$ to $Y$.
Determine the distance $p$ of point $Y$ from the left-hand edge of the top plate.