# Torque: Second Condition of Equilibrium

## Torque: Second Condition of Equilibrium

A torque is an influence, which tends to change the rotational motion of an object. One way to quantify a torque is force applied times the lever arm.

In this experiment we consider the systems in equilibrium and its applications and how the forces acting on the system affect torque. To serve as a guide there are objectives set in performing this experiment. First objective is by the second condition applied to the systems of equilibrium and the second objective is to ponder second condition of equilibrium’s use and importance.

MATERIALS AND METHODS

Setting up the apparatus given with the following materials: Phywe model balance, Pasco Scientific Mass and Hanger Set (ME-8967 & ME-9348), Meterstick, Protactor, Weight Pans and Spring Balance.

(Figure 1. The following materials needed for accomplishing experiment 204.)

The first part of the experiment, which is the determining the weights of the pan. Setting up the apparatus, make sure that the model balance is stagnant to avoid errors. Mark the pans as P1 and P2 and place the certain weight indicated on the table on the P1 only and adjust the pans on the beam so that the system is in equilibrium. Measure L1 from the center of the beam to the P1 and L2 from the center of the beam to P2. Now remove the weight from P1 and add the certain weight this time in P2 and adjust the pans again for equilibrium. Now measure L3 from the center to P1 and L4 from the center to P2. You get these equations in solving for the actual value of P1 and P2: for equation 1 and for equation 2.

(Figure 2. The first part of the experiment, determining the weights of the pan.)

The second part of the experiment, which is determining the force needed to be in equilibrium. You only need a single pan on this part adding 50gm weight at the left side of the beam. Place the spring balance on an upright position and now pulling it. See to it that the angle of inclination of the spring balance is not perpendicular or less than 90o. Record the reading on the spring balance as the Force or F and measure L1 from the center of the beam to the pan and L2 from the center to the hook of the spring balance and lastly measure the angle of inclination using the protractor. For trial 2 we set the spring balance on the right side of the beam on a downward position with the same procedure as for trial 1. We compute for the force with the equation:

(Figure 3. The second part of the experiment, determining the force needed to be in equilibrium for trials 1 and 2.)

For the last part of the experiment, which is determining the weight of the beam. Now we make use of the second hole of the beam from its left as its axis of rotation. Place a 50gm weight on P1. Adjust the pan to where the system would be in equilibrium. Now measure L1 from the center of the stand to P1 or the weight and L2 from the center to the second hole of the beam. Repeat the process for 3 trials adding a 10gm weight per trial. We compute for the weight of beam with the equation:

(Figure 4. For the last part of the experiment, determining the weight of the beam.)

DISCUSSION & CONCLUSION

The greater the weights added to the pan, then the closer it has to be to the axis of rotation to maintain the system in equilibrium. By definition, torque is the product of force and the lever arm. Greater weights exert more force; therefore to maintain the torque the lever arm should decreased. The different factors needed to determine the torque applied to a body depend on the following; a convenient axis, all the exerted forces including weight, the angle of the applied force, and lastly the distance from the force to the axis. The support of the beam must be transferred to the second whole Knowing that the axis is in the center; its weight does not exert any torque on the system because lever arm is zero.

By changing the location of the axis, we are able to compute for the unknown weight of the beam using principles of the Second Condition of Equilibrium. Translational equilibrium means that the system does not change its location. For a rigid translational equilibrium means that at least one point in the body is stationary. While in rotational equilibrium the system does not rotating about any axis. To keep a body in translational and rotational equilibrium, the net forces and the net torques must be equal to zero or simply balance the forces and torques.

ACKNOWLEDGMENT & REFERENCE

It is my privilege to acknowledge the generosity of our professor Engr. Ricardo de Leon for instructing us all throughout the experiment. I would like to express my special thanks to my groupmates: Ivan Inmenzo, Ian Sumague, Dave Paglinawan, Florence Florendo and Aldrin Mosteyro for our teamwork. These experiments would not be possible without their great cooperation. All the efforts are appreciated and as it helped us communicate and do well in our activities.

Most especially it is from my sincerest and deep gratitude to Almighty God for His influences and for surrounding us with great wisdom.

UogeulPh Editors. (n.d.). What is Torque? Retrieved February 7, 2015, from http://www.physics.uoguelph.ca/tutorials/torque/Q.torque.intro.html

HyperPhysics Editors. (n.d.). Torque. Retrieved February 7, 2015, from http://hyperphysics.phy-astr.gsu.edu/hbase/torq.html

Feynman, R. P. et al. (2007) The Feynman Lectures on Physics, Vol. 1. http://scienceworld.wolfram.com/physics/

(Figure 5. Group 4 finished with the experiment.)