Answer:
Negative work
Explanation:
The work-energy theorem states that the work of the resultant forces acting on a particle modifies its kinetic energy:
[tex]W=\Delta K\\W=\frac{mv_f^2}{2}-\frac{mv_0^2}{2}\\W=\frac{m}{2}(v_f^2-v_0^2)\\W=\frac{m}{2}((7\frac{m}{s})^2-(15\frac{m}{s})^2)\\W=\frac{m}{2}(-178\frac{m^2}{s^2})[/tex]
Since the mass of the ball has to be positive, the work is negative.
