Question

3. The position of a particle moving along the x-axis is given by x = 7t^2 + 2t^3, where x is in meters and t is in seconds. Determine the following, when t = 1.4 s:

(a) The position (2) (b) The velocity (2) (c) The acceleration (2)

Answer 1

a)

$x=7t^2+2t^3,$

$x(1.4)=19.2~m,$

b)

$v=\dot x=14t+6t^2,$

$v(1.4)=31.4~\frac ms,$

c)

$a=\dot v=14+12t,$

$a(1.4)=30.8~\frac m{s^2}.$