Question

1. A moving particle with a charge of 6.52 is accelerated through a potential difference of 234mV. Find the final velocity of the particle if its initial velocity is 5.24m/s. (mass of the charged particle=154g).

2. An unpolarized beam passes through a system containing three ideal polarizers. the first polarizer is oriented with a horizontal transmission axis, the second one has its transmission axis at 70.4degrees from the horizontal, and the third filter has a vertical transmission axis. What percent of the light gets through this combination of polarizers?

Answer 1

Question 1

When a particle is accelerated through a potential difference, it gains a kinetic energy equal to the product of the charge and the potential difference. Therefore, its final kinetic energy is the sum of its initial kinetic energy and the energy gained from the potential difference.

Question 2

First, we note that the first polarizer is a horizontal polarizer. Here, since we do not know the angle of the light, we cannot use Malus' Law.

However, we know that unpolarized light can be considered to have an equal amount of horizontal and vertical polarization, and hence if it were to be passed through a horizontal polarizer, it would lose half its intensity, as the vertical component is filtered out.

Hence, after the first polarizer, the intensity is

For every consecutive polarizer, the angle is measured with respect to the previous one.

Therefore, the intensity after passing through the other two is