David Sang Solutions for Chapter: Describing Motion, Exercise 8: Question

A car travels for $10 \mathrm{s}$ at a steady speed of $20 \mathrm{m}/\mathrm{s}$ long  a straight road. The traffic lights ahead change to red, and the car slows down with a constant deceleration, so that it halts after a further $8 \mathrm{s}$.

Draw a speed-time graph to represent the car's motion during the $18 \mathrm{s}$ described.

A car travels for $10 \mathrm{s}$ at a steady speed of $20 \mathrm{m}/\mathrm{s}$ long  a straight road. The traffic lights ahead change to red, and the car slows down with a constant deceleration, so that it halts after a further $8 \mathrm{s}$.

Use the graph to deduce the car's deceleration as it slows down.

A car travels for $10 \mathrm{s}$ at a steady speed of $20 \mathrm{m}/\mathrm{s}$ long  a straight road. The traffic lights ahead change to red, and the car slows down with a constant deceleration, so that it halts after a further $8 \mathrm{s}$.

Use the graph to deduce how far the car travels during the $18 \mathrm{s}$ described.