Work for Dinosaur Speed Geocache

This is the work for the geocache we did today. The geocache description instructed us to measure the stride length and footprint length of some dinosaur tracks at the Dinosaur Ridge hike outside of Denver, Colorado. The kids and I looked at both the thinner Ornithomimus tracks and the thicker Iguanodontid tracks. Here’s the work, done in R:

First, set up a table of the data. The units for stride length and footprint length are meters.

dino_data <- data.frame(species = c("Ornithomimus", "Iguanodontid"),
                        stride_length = c(1.041, 1.063),
                        footprint = c(0.18, 0.415))

dino_data

##        species stride_length footprint
## 1 Ornithomimus         1.041     0.180
## 2 Iguanodontid         1.063     0.415

Second, create an estimate of the height.

dino_data$height <- dino_data$footprint * 4
dino_data

##        species stride_length footprint height
## 1 Ornithomimus         1.041     0.180   0.72
## 2 Iguanodontid         1.063     0.415   1.66

Third, create the velocity estimates in meters per second.

g <- 9.81 # meters per second
dino_data$mps <- 0.25 * (g ^ 0.5) * 
  dino_data$stride_length^1.67 * 
  dino_data$height^(-1.17)
dino_data

##        species stride_length footprint height       mps
## 1 Ornithomimus         1.041     0.180   0.72 1.2298105
## 2 Iguanodontid         1.063     0.415   1.66 0.4792461

Finally, convert to miles per hour by multiplying meters per second by 3600 seconds per hour and 1/1609 miles per meter.

dino_data$mph <- dino_data$mps * 3600 / 1609

Here are the results:

dino_data

##        species stride_length footprint height       mps      mph
## 1 Ornithomimus         1.041     0.180   0.72 1.2298105 2.751596
## 2 Iguanodontid         1.063     0.415   1.66 0.4792461 1.072272

Thanks for a fun cache!