What force must be applied to lift the load?

[Jtappan]

Homework Statement

A rod is being used as a lever as shown. The fulcrum is 1.2 m from the load and 2.4 m from the applied force. If the load has a mass of 11.6 kg, what force must be applied to lift the load?
____ N

Homework Equations

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The Attempt at a Solution

When doing this problem do you need to put the rock as negative radius? or are you using two different equations?

 

[Dick]

This is a simpler version of the last problem you posted. Read my response to that first. You have to balance both total vertical force AND torque. You can put the center to compute torques from anyplace you want, but the fulcrum is convenient. In which case, yes, one distance is positive and one is negative.

 

[ogb p]

I would approach this problem by using the principles of mechanics, specifically the laws of motion and the concept of torque. To lift the load, a force must be applied to the lever. This force must overcome the weight of the load as well as any friction or resistance in the system. The amount of force required can be calculated using the equation F = mg, where F is the force needed, m is the mass of the load, and g is the acceleration due to gravity (9.8 m/s^2). In this case, the force needed would be (11.6 kg)(9.8 m/s^2) = 113.68 N.

However, this is not the only force acting on the system. The lever is acting as a simple machine, with the fulcrum acting as the pivot point. This means that the lever will also experience a torque, or rotational force, due to the applied force and the distance from the fulcrum. The equation for torque is T = F x d, where T is torque, F is force, and d is the distance from the fulcrum. In this case, the force applied is the same as the force needed to lift the load (113.68 N), and the distance from the fulcrum is 2.4 m. This means that the torque acting on the lever is (113.68 N)(2.4 m) = 272.83 Nm.

In summary, the force required to lift the load is 113.68 N, but this is not the only force acting on the system. The lever will also experience a torque of 272.83 Nm due to the applied force and the distance from the fulcrum.