An alpha particle is accelerated in an electric field between metal plates P and Q - Scottish Highers Physics - Question 11 - 2019

To find the potential difference (V) across the plates, we can use the formula relating kinetic energy (KE) and potential difference:

$KE = qV$

where:

• KE is the kinetic energy gained by the alpha particle (8.0 × 10⁻¹⁶ J).
• q is the charge of the alpha particle (3.2 × 10⁻¹⁹ C).

Rearranging the formula gives us:

$V = \frac{KE}{q}$

Substituting the known values:

$V = \frac{8.0 \times 10^{-16}}{3.2 \times 10^{-19}}$

Calculating this gives:

$V = 2.5 \times 10^{3} \text{ V},$

which can be expressed in scientific notation as 2.5 × 10⁴ V. Therefore, the potential difference across plates P and Q is:

D 2.5 × 10⁻⁴ V.