Velocity-Time Graphs
Example
- Total displacement = 600m
- \(600=\frac{1}{2}(T+5T+40+5T)\times 8\)
- \(600=4(11T+40)\)
- \(150=11T+40\)
- \(11T=110\)
- \(T=10\)
Exercise 9B
Q1
- The athelete accelerates at \(\frac{9}{4}ms^{-1}\)
- \(\frac{9\times4}{2}+(9\times 8)=18+72=90m\)
Q2
- .
- \(10\times30=300m\)
\(12\times 10=120m\), \(\frac{120m}{2}=60m\)
\(300m+60m=360m\)
Q3
- \(\frac{8}{20} ms^{-2}\)
- \(\frac{8}{15}ms^{-2}\)
- \(\frac{8\times 20}{2}+\frac{8\times15}{2}+40\times 8=80+60+240=380m\)
Q4
- .
- Start to finish is 2400m.
\(\frac{30\times15}{2}+\frac{30\times25}{2}=225+375=600m\)
\(2400-600=1800\)
\(\frac{1800}{30}=60\)
So if \(T=60\), total time = \(15+25+60=\) 1 minute and 40 seconds.