Answer:
[tex]\large \boxed{\text{0.25 kg}}[/tex]
Explanation:
We can use the formula for momentum to calculate the mass.
[tex]\begin{array}{rcl}p & = & mv\\2 & = & m \times 8\\m & = & \dfrac{2}{8}\\\\& = & \textbf{0.25 kg}\\\end{array}\\\text{The mass of the ball is $\large \boxed{\textbf{0.25 kg}}$}[/tex]
