Physics equations/Kinematics/More problems

Example 1: A particle starting at the origin has moved 27 m in 9 s. Find ${\bar {v}}$.

${\bar {v}}={\frac {x_{f}-x_{i}}{t_{f}-t_{i}}}={\frac {27\ \mathrm {m} -0\ \mathrm {m} }{9\ \mathrm {s} -0\ \mathrm {s} }}=3\ \mathrm {m} /\mathrm {s}$

Example 2: A particle starting 23 m from the origin has moved to 43 m in 5 s. Find ${\bar {v}}$.

${\bar {v}}={\frac {x_{f}-x_{i}}{t_{f}-t_{i}}}={\frac {43\ \mathrm {m} -23\ \mathrm {m} }{5\ \mathrm {s} -0\ \mathrm {s} }}={\frac {20\ \mathrm {m} }{5\ \mathrm {s} }}=4\ \mathrm {m} /\mathrm {s}$