Question

Two children push on opposite sides of a door during play. Both push horizontally and perpendicular to the surface of the door. One child pushes with a force of 17.5 N at a distance of 0.59 m from the hinges, and the second child pushes at a distance of 0.47 m.
What force must the second child exert to keep the door from moving? Assume friction is negligible.

Answer 1

Answer:

F₂ = 21.97 N

Explanation:

this is a rotational equilibrium exercise, let's write the formula

         ∑ τ = 0

          F₁ d₁ - F₂ d₂ = 0

force F₁ is 17.5 N and its distance d₁ = 0.59m, the distance d₂ = 0.47m

          F₂ = F₁ d₁ / d₂

          F₂ = 17.5 0.59 / 0.47

          F₂ = 21.97 N