Pressure-Force Cross-Scan - Electromagnetic Waves and Radiation Step by Step

A pressure-force scan varies pressure across rows while holding area fixed, showing how the force F = P * A scales linearly row by row. The arithmetic is exact only for the stated pressures, areas, and rows in the ideal uniform-loading model. Real beams add finite bandwidth, alignment error, beam-profile nonuniformity, detector calibration, surface assumptions, and measurement uncertainty.

Pressure is scanned across irradiance and mode, then force across area. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Pressure divides irradiance by speed

For an absorber, the pressure is the normal irradiance over the training speed. A mirror doubles that momentum change.

p=I/c=6/6=1\ \text{Pa}

Mode and irradiance both change pressure

The rows separate two effects: more irradiance raises pressure, and the mirror mode doubles the absorber value.

\begin{array}{c|c|c|c}\text{mode}&I&c&p\\\text{absorber}&3\ \text{W}/\text{m}^{2}&6\ \text{m}/\text{s}&\frac{1}{2}\ \text{Pa}\\\text{absorber}&6\ \text{W}/\text{m}^{2}&6\ \text{m}/\text{s}&1\ \text{Pa}\\\text{mirror}&6\ \text{W}/\text{m}^{2}&6\ \text{m}/\text{s}&2\ \text{Pa}\\\end{array}

Pressure becomes force only after area is included

Pressure alone is not a force. The illuminated surface area is the second checked input.

\begin{array}{c|c|c}p&A_s&F\\1\ \text{Pa}&2\ \text{m}^{2}&2\ \text{N}\\1\ \text{Pa}&3\ \text{m}^{2}&3\ \text{N}\\1\ \text{Pa}&6\ \text{m}^{2}&6\ \text{N}\\\end{array}