If a car travels 50 m distance in 4s with a acceleration of 5 m/s2, then what was its initial speed?
Using the second equation of motion: s = ut + at2
where: s = distance covered =50 m
u = initial velocity = ?
a = acceleration = 5 m/s2
t = time = 4s
s = ut + at2
50 = u x 4s + x 5 x 42
50 = u x 4s + 40
50 – 40 = u x 4s
10 = u x 4s
u = m/s = 2.5 m/s