Answer :
Final answer:
The wheelbarrow with 71 kg of concrete will experience the greatest change in speed because it has the lowest mass and the same force is applied to each wheelbarrow.
Explanation:
The question you're asking involves concepts from physics, specifically the relationship between force, mass, and acceleration described by Newton's Second Law of Motion. If three students push wheelbarrows with the same amount of force across a football field, and the wheelbarrows have different masses, the wheelbarrow with the least mass will have the greatest change in speed. This is because acceleration is inversely proportional to mass when the force applied is constant. Therefore, the wheelbarrow with 71 kg of concrete will have the greatest change in speed, since it has the lowest mass.