Answer: 5.48 meters per second.
Explanation: since the kinetic energy and force applied have been given, you can use the concept of kinetic energy.
Formula: KE= 1/2mv^2
rearrange the formula to solve for speed
Speed = √(2 * (kinetic energy) / (mass))
Speed = √(2 * 7.5 J / (0.5 N))
Speed ≈ √(15) ≈ 3.87 meters per second (m/s)