Answer:
The correct option is;
B. 8 m, because he has to apply less force over a greater distance
Explanation:
In the given question, in order for the student to lift the boxes onto the tuck with less amount of force, he applies the principle of Mechanical Advantage
The mechanical advantage is given by the measure by which a force is amplified through the use of a tool
Given that the work done = The force × The distance, we have
F₁ × d₁ = F₂ × d₂, which gives;
d₁/d₂ = F₂/F₁
Where;
F₁ = The input force
F₂ = The output force
d₁ = The input distance
d₂ = The output distance
The Mechanical advantage, MA = d₁/d₂ = F₂/F₁
Therefore, when the input distance is increased the input force will be reduced for a given output force
