1 joule = 10

1 erg = kinetic energy of a mosquito in full flight!

1 gram of TNT (about a thimbleful) releases about 4 X 10

Let's work out the KE of a bicyclist going 20 km/h.

20 km/h = 20 X 10

Suppose the bicycle plus cyclist weigh 100 kg = 1 X 10

KE = mv

Now suppose the bicyclist is going much faster, say 100 km/h (by holding on to a car, say). His velocity is 5 times more, so his KE is 25 times more. So now his KE is 4 X 10

Suppose we put him in low Earth orbit. This requires 7 km/sec = 7 X 10

KE = mv