collision – n. an act of colliding, such as a crash in which two or more things or people hit each other

bang – n. a sudden, loud noise

compact – adj. closely or firmly joined together

calculation – n. an estimate or prediction

ripple – n. something that passes or spreads through or over someone or something; a shape having small waves

detector – n. a device that can tell if a substance or object is present; a device that measures the presence of something

thud – n. a loud sound made especially when a heavy object hits something