Question

A motorbike reaches a speed of 20 m/s over 60m, whilst

Answer 1

Initial speed = 2√10 m/s

Further explanation  

Linear motion consists of 2: constant velocity motion with constant velocity and uniformly accelerated motion with constant acceleration  

An equation of uniformly accelerated motion  

V = vo + at  

Vt² = vo² + 2a (x-xo)  

x = distance on t  

vo / vi = initial speed  

vt / vf = speed on t / final speed  

a = acceleration  

vf=20 m/s

d = 60 m

a = 3 m/s²

$\tt vf^2=vi^2+2.ad\\\\20^2=vi^2+2\times 3\times 60\\\\400=vi^2+360\\\\40=vi^2\\\\vi=\sqrt{40}=2\sqrt{10}~m/s$