An impelling force or strength:
— The car's momentum carried it off the road.

synonym: impulse.

Roget 276: impulse, impulsion, impetus; momentum; push, pulsion^†, thrust, shove, jog, jolt, brunt, booming, boost [U.S.], throw; explosion etc. (violence) 173; propulsion etc. 284.    percussion, concussion, collision, occursion^†, clash, encounter, cannon, carambole^†, appulse^†, shock, crash, bump; impact; elan; charge etc. (attack) 716; beating etc. (punishment) 972.    blow, dint, stroke, knock, tap, rap, slap, smack, pat, dab; fillip; slam, bang; hit, whack, thwack; cuff etc. 972; squash, dowse, swap, whap^†, punch, thump, pelt, kick, punce^†, calcitration^†; ruade^†; arietation^†; cut, thrust, lunge, yerk^†; carom, carrom^†, clip [Slang], jab, plug [Slang], sidewinder [U.S.], sidewipe^†, sideswipe [U.S.].    hammer, sledge hammer, mall, maul, mallet, flail; ram, rammer^†; battering ram, monkey, pile-driving engine, punch, bat; cant hook; cudgel etc. (weapon) 727; ax etc. (sharp) 253.    [Science of mechanical forces] dynamics; seismometer, accelerometer, earthquake detector.    ... show more

Polish: impet, rozmach

The product of a body's mass and its velocity.

Dutch: vaart, impuls