Answer:
The initial velocity of this shark is [tex]8.0\; \rm m \cdot s^{-1}[/tex]. (Assuming that the unit of the acceleration in this question is [tex]\rm m\cdot s^{-2}[/tex].)
Explanation:
Let [tex]a[/tex] denote the acceleration of this shark.
Let [tex]v_0[/tex] denote the initial velocity of this shark.
Assume that the acceleration [tex]a[/tex] of this shark is constant (as it is in this question.) Over a period of time [tex]t[/tex], the shark would have travelled a distance of:
[tex]\displaystyle x = \frac{1}{2}\, a\, t^2 + v_0\, t[/tex].
This question states that:
This question is asking for [tex]v_0[/tex], the initial velocity of this shark at the beginning of this [tex]0.8[/tex]-second period. Substitute the three known values into the equation:
[tex]\displaystyle 11.52 = \frac{1}{2}\times 16\times (0.8)^2 + 0.8\, v_0[/tex].
Solve for [tex]v_0[/tex]:
[tex]v_0 = \displaystyle \frac{11.52 - (1/2) \times 16 \times (0.8)^2}{0.8} = 8.0\; \rm m \cdot s^{-1}[/tex].
