Let u = upward initial speed of the flea.
At the maximum height of h = 0.550 m, the vertical velocity is v = 0.
Therefore, from the formula
v² = u² - 2gh,
obtain
0 = u² - 2*(9.8 m/s²)*(0.55 m)
u² = 10.78 m²/s²
u = 3.283 m/s
Answer: The initial upward speed is 3.28 m/s (nearest thousandth)
