The position of an object moving along x- axis is given by x = α + βt2 where α and β are constants with appropriate dimensions and t is time in seconds. The average velocity between t = 2s and 4s is 12 m/s. If α = 8m then the value of β is
1
0.5 m/s2
2
2 m/s2
3
4 m/s2
4
5 m/s2