Average Speed
Posted: Wed Mar 11, 2026 5:40 pm
\(\bar{s} = \dfrac{\Delta\, x}{\Delta\, t}\)
\(where\)
\(\bar{s} = avg\,\,speed\)
\(\Delta\,x = d\,\,(distance) = change\,\,in\,\, position\)
\(so\)
\(\Delta\,\,x = d = x_{f} - x_{o} = \,\,x\,(final) - x\,(initial)\)
\(and\)
\(\Delta\,t = change\,\,in\,\,time\)
\(so\)
\(\Delta\,\,t = t_{f} - t_{o} = \,\,t\,(final) - t\,(initial)\)
\(m = meter,\,\, km = kilometer,\,\, s = second,\,\, min = minute\)
\(and\)
\(\Delta\,\,x = d = x_{f} - x_{o} = 2000\,\,m - 0\,\,m = 2000\,\,m\)
\(\Delta\,\,t = t_{f} - t_{o} = 120\,\,s - 0\,\,s = 120\,\,s\)
\(so\)
\(\bar{s} = \dfrac{2000 \,\,m}{120\, s} = \dfrac{16.7\,\,m}{s}\)
\(where\)
\(\bar{s} = avg\,\,speed\)
\(\Delta\,x = d\,\,(distance) = change\,\,in\,\, position\)
\(so\)
\(\Delta\,\,x = d = x_{f} - x_{o} = \,\,x\,(final) - x\,(initial)\)
\(and\)
\(\Delta\,t = change\,\,in\,\,time\)
\(so\)
\(\Delta\,\,t = t_{f} - t_{o} = \,\,t\,(final) - t\,(initial)\)
\(m = meter,\,\, km = kilometer,\,\, s = second,\,\, min = minute\)
\(\bar{s} = \dfrac{\Delta\, x}{\Delta\, t}\)A car travels \(2000\, m\, (2\, km)\) in \(120 \,s\, (2\, min).\) What is the avg speed?
\(and\)
\(\Delta\,\,x = d = x_{f} - x_{o} = 2000\,\,m - 0\,\,m = 2000\,\,m\)
\(\Delta\,\,t = t_{f} - t_{o} = 120\,\,s - 0\,\,s = 120\,\,s\)
\(so\)
\(\bar{s} = \dfrac{2000 \,\,m}{120\, s} = \dfrac{16.7\,\,m}{s}\)