A device has been proposed as a momentum sensor for molecular beams. A molecular beam when it hits a solid object imparts a force, P, to the object. In our case the object is a pin-clamped beam. The force bends the beam and the bending is detected using a light source that reflects off the surface of a beam. The angle of reflection is measured on a circular screen at some distance from the beam. Determine the sensitivity of the device (S/P) assuming L = 300 mm, a = 85 mm, b = 0.5L, E = 70 GPa, and R = 1.5 m. The beam has a 4-mm by 0.9-mm cross-section, and bends about the weak axis. R P, force of the molecular beam b a