Final answer:
To find the force that the weed exerted on the tool, the torque equation τ = F × r should be used; however, the distance (r) from the point of application to the pivot is needed to solve for the force (F).
Step-by-step explanation:
To calculate the force that the weed exerted on the tool, we need to use the definition of torque. Torque (τ) is the product of the force (F) applied and the distance (r) from the pivot point, which in this case is the center of the bolt or the point where the tool grips the weed. Given that the torque is 1.39 newton-meters (n·m) and assuming the force was applied perpendicularly, we can set up the equation τ = F × r.
However, we are missing the distance (r) value in the provided information to solve for force directly in this case. If we had the distance, we could rearrange the equation to solve for F as F = τ / r.