# Speed

This entry relates to the physical concept of speed; for the film, see Speed (1994 film)

Speed is the rate of motion, or equivalently the rate of change in position, often expressed as distance d traveled per unit of time t.

## Quotes

• In Einstein’s corrected formula m has the value ${\displaystyle m={\frac {{m}_{0}}{\sqrt {1-v^{2}/c^{2}}}}}$ where the “rest mass” m0 represents the mass of a body that is not moving and c is the speed of light, which is about 3×105 km⋅sec−1 or about 186,000 mi⋅sec−1.

• Richard Feynman, The Feynman Lectures on Physics, Vol. I, Ch. 15. The Special Theory of Relativity
• Be wise with speed;
A fool at forty is a fool indeed.
• Ares (The God of War) hates those who hesitate.
• Heraclidæ (c 428 BC) line 722.
• Euripides Alternate translation : Ares hates the sluggard most of all. (translated by David Kovacs)
• It would be relevant … to point out the sinister part played by speed, by belief in speed as a value, by, in a word, a kind of impatience that has had a profound effect in changing even the very rhythms of the life of the spirit for the worse.
• Ease and speed in doing a thing do not give the work lasting solidity or exactness of beauty.
• Speed has never killed anyone. Suddenly becoming stationary, that's what gets you.
• Speed is the essence of war. Take advantage of the enemy's unpreparedness; travel by unexpected routes and strike him where he has taken no precautions.