Final answer:
The lever arm is the distance from the axis of rotation to where the force is applied on mass m1, critical in the calculation of torque.
Step-by-step explanation:
The lever arm for the torque produced by mass m1 is the distance from the axis of rotation to m1, which is also known as the radius of the lever. This perpendicular distance is crucial in calculating torque because torque is defined as the product of this lever arm distance and the force applied perpendicular to it. In mathematical terms, torque (T) is expressed as T = rF sin θ, where r is the lever arm, F is the applied force, and θ is the angle between the lever arm and the force vector. When considering a physical lever, this distance is measured from the fulcrum, or pivot point, to where the force is applied on the lever. If using a free-body diagram, the lever arm is the vector from the axis of rotation to the point where force is exerted, and this distance plays a critical role in determining the mechanical advantage (MA) of the lever.
The lever arm for the torque produced by mass m1 is (c) the distance from m1 to the fulcrum.
The lever arm is the distance between the point of rotation (fulcrum) and the location where force is applied. In this case, the mass m1 is providing the force and the lever arm is the distance from m1 to the fulcrum.