# Fast

Fun fact: The escape velocity needed to leave Earth’s gravity pull is 11.2 km/sec (7 miles/sec). At Earth, the escape velocity needed to leave the solar system is 42.1 km/sec (26 miles/sec). A marathon every second? I find this alarming.

I can’t help but wonder if the Roadrunner from Looney Tunes could escape Earth’s gravity. Can anyone find figures on The Roadrunner’s estimated top speed?

### 6 thoughts on “Fast”

• 4/22/2010 at 8:07 am

This is a tricky search because other high-speed Roadrunners include an ISP and a muscle car.

Some quick math would estimate that in order for the runner’s legs to be “blurred” to the human eye, each leg would be moving at least 100 strides per second. Given the bird’s (cartoon version) height estimate or 2 ft., each stride may be 12″ each, times two legs = 200ft/sec, which is 136mph. But then he says “beep beep” and disappears, and the pavement leaps off the ground, and a small sonic boom is heard, which is clearly even faster than the rated performance enhancement of ACME Speed Pills.

• 4/22/2010 at 9:07 am

Nice investigative work. As we of course know, 136 miles per hour is not remotely close to 7 miles a second. Though your note about the leaping pavement makes me wonder if we are underestimating the speeds.