Physics Unit 2 Revision (Higher tier)

Distance-time and velocity-time graphsDistance-time graphs tell you how anobjects distance is changing over time.If there is a smooth slope on your graphthen the object is moving at a constantspeed. If there is a flat line then thereis no movement. A steeper slope meansa faster speed. If the slope isdownwards the object is returning tothe starting position. If there is anupwards curve (downward curve () on a distance time graph then the object is accelerating, a) means it is decelerating.In order to work out thespeed from the slope youchoose a section of theslope and determine whatsize it is relative to theaxis. Since speed isdistance ÷ time you thenuse those values from theslope. So in this caseSpeed = 4m ÷ 4s = 1m/sSpeed is how fast you are travelling and velocity is your speed in a givendirection.Distance (m)86420Distance-timegraph0 2 4 6 8 Time (s)Velocity-time graphs tell you how an objectsvelocity is changing over time. If there is asmooth slope on your graph then the objectis accelerating. If there is a flat line thenthe object is moving at a constant speed. Asteeper slope means a larger acceleration. IfVelocity (m/s)8642Velocity-timegraph00 2 4 6 8 Time (s)