Rain Streaks: How Fast Does It Rain?

October 14, 2010


Photographer: John Adam; John’s Webpage
Summary Author: John Adam

This rather pedestrian photograph was taken from a sheltered area outside the Mount Washington Resort, in Bretton Woods, New Hampshire. Thanks to the heavy rains from Tropical Storm Nicole on September 30, Mount Washington was nowhere to be seen! Nevertheless, it seemed like fun to “guesstimate” the speed of the raindrops, given that the exposure time for the shot was 1/200 second and an estimate of the width of my sneaker (you don’t need to know my actual shoe size to do this.). My foot and the raindrops shown were about the same distance from the camera. I have assigned this as an extra-credit problem for my pre-calculus students, but interested readers can do it for the love of arithmetic! Click here for answer [pdf].

Photo details: Camera Maker: OLYMPUS IMAGING CORP.; Camera Model: SP570UZ; Focal Length: 14.9mm; Aperture: f/3.9; Exposure Time: 0.0050 s (1/200); ISO equiv: 800; Exposure Bias: none; Metering Mode: Matrix; Exposure: Creative Program (based towards depth of field); White Balance: Auto; Flash Fired: No; Color Space: sRGB.