Question

In a 41 s interval, 580 hailstones strike a glass window of area 1.346 m2 at an angle 31◦ to the window surface. Each hailstone has a mass of 7 g and speed of 6.7 m/s. If the collisions are elastic, find the average force on the window. Answer in units of N.

Answer 1

N = hailstones / sec = 580 / 41 = 14.1 stones / sec

mass = .007 kg

v = 6.7 m/s * sin 31 = 3.45 speed of stones perpendicular to surface

Δp = 2 m Δv change in momentum dur to striking window

F = N Δp force required to repel hailstones

F = 2 N m Δv = .68 N force on window pane

Pressure = force / area (don't need window area for force)