A student sets up an experiment to investigate the interaction between two trolleys on a smooth, horizontal track - Scottish Highers Physics - Question 3 - 2022

Using the formula for force:

$F = \frac{\Delta p}{\Delta t}$

Rearranging gives:

$\Delta t = \frac{\Delta p}{F}$

Where:

• (\Delta p = 0.35 , kg , m/s)
• (F = 6.25 , N)

Substituting the values in:

$\Delta t = \frac{0.35}{6.25} = 0.056 \, s$

Using conservation of momentum:

$m_X v_{X_i} + m_Y v_{Y_i} = m_X v_{X_f} + m_Y v_{Y_f}$

Where:

• (m_X = 0.50 , kg)
• (v_{X_i} = 0.40 , m/s)
• (m_Y = 0.25 , kg)
• (v_{Y_i} = 0.40 , m/s)
• (v_{Y_f} = 1.80 , m/s)

Substituting values:

To determine if the interaction was elastic, the student should compare the total kinetic energy before and after the interaction. If the total kinetic energy remains the same, the interaction is elastic. However, if the total kinetic energy decreases, then it is inelastic.

The effect is known as the photovoltaic effect.

When light photons strike the photodiode, electrons gain energy and move from the valence band to the conduction band. This movement creates a flow of current and generates a potential difference across the diode, ultimately converting light energy into electrical energy.