【Impact】 ,  【impingement】 ,  【collision】 ,  【clash】 ,  【shock】 ,  【concussion】 ,  【percussion】 ,  【jar】 ,  【jolt】  mean a forcible or enforced contact between two or more things, especially a contact so violent as to affect seriously one or the other or all of the persons or things involved.

【Impact】 , though it often means this and no more, may be used more generally to imply contact between two things, one of which at least is driven or impelled in the direction of the other and produces a definite effect on it, though not necessarily a physical effect or one that results in injury.

【Impingement】  often means little more than  【impact】 , but distinctively it may imply a sharper or more forcible contact than  【impact】  <each little  【impingement】  of sound struck on her consciousness —Langley >  or may carry, as  【impact】 does not, a suggestion of encroachment.

【Collision】 implies the coming together of two or sometimes more things with such force that both or all are more or less damaged or their progress is seriously impeded.

【Collision】 may be used when the things which come together so as to seriously affect one another are immaterial rather than physical entities.

【Clash】  primarily applies to the sharp discordant sounds produced by an 【impact】 or series of impacts between two or more bodies, especially metallic bodies; it is often used in preference to  【collision】 when two or more things come into contact with one another in such a manner that noises of crashing and jangling are more apparent than the destruction or ruin wrought.

【Clash】 , also, is used more often of immaterial things (as beliefs, theories, and ideas) which are irreconcilable or incompatible and lead to violent conflict or controversy.

【Shock】 denotes the effect (as shaking, rocking, agitating, or stunning) produced by an 【impact】 or 【collision】 . It may imply a physical, mental, or emotional effect, but in every case it carries a strong suggestion of something that strikes or hits with force and often with violence.

【Concussion】 , found more often than  【shock】 in learned and technical use, may mean a blow or 【collision】 but more often suggests the shattering or disrupting effects of a 【collision】 or explosion or the stunning weakening effects of a heavy blow.

【Percussion】  implies a deliberate or intentional striking, knocking, or tapping for the sake of something (as a sound, an explosion, or a vibration) produced by the 【impact】 of such a stroke, knock, or tap; thus,  【percussion】  instruments in an orchestra are those played by striking (as a drum, a gong, cymbals, bells, or a tambourine); a  【percussion】  bullet contains a substance that is exploded by  【percussion】 ; a doctor by  【percussion】  (that is, by tapping or striking the chest or abdomen) discovers by the sounds produced the condition of a patient′s lungs or abdominal organs.

【Jar】 applies to the painful and disturbing but not necessarily injurious shaking suffered as a result of a 【collision】 , 【clash】 , 【shock】 , or 【concussion】 .

【Jolt】 carries a stronger implication of jerking out of place than of shaking and therefore carries a clearer suggestion of loss or near-loss of balance.