# A particle moves along a semicircle of radius 10 m in 5 seconds. The average velocity of the particle in m/s is?

$(a)\;2 \pi m/s \quad (b)\;4 \pi m/s \quad (c)\;2 m/s \quad (d)\;4 m/s$

Average velocity = Total Displacement / Time taken
Displacement = 2 x Radius = 2 x 10m = 20m.
Time taken = 5s
$\Rightarrow$ Average velocity = 20/5 = 4 m/s.
edited Aug 11, 2014