Experiment No. 2: Resultant and Equilibrant Forces

ABSTRACT Using a force table, we mounted a ring to serve as the object forces act on. We attached three strings around the ring and to each end of the strings designated a pulley with corresponding weight holders situated in different directions. We proceeded to balance the weights each weight holder had to obtain equilibrium with the ring stable in the center and thereby obtaining a specific magnitude and directions for each three concurrent forces. With all three forces determined, we derived the experimental resultant forces by computing for the negative vector of any one of the three forces given the two other forces. Upon calculating the experimental resultant forces by computing for the negative vectors of the said resultant forces. Finally, we came up with the computed resultant forces of the three given concurrent forces by using the component method.

QUESTIONS AND ANSWERS

1. Differentiate the Resultant and Equilibrant of two forces.

A resultant force would cause a stationary object to start moving or an object with a given velocity to speed up or slow down or change directions such that velocity of the object changes. It is usually computed by the component method given two or more known forces. If a resultant force acts on an object then that object can be brought into equilibrium by applying an additional force that exactly balances this resultant. Such a force called the equilibrant force acting on the object. Therefore, the equilibrant force is the negative vector of the resultant force.

2. If the three concurrent forces are in equillibrium, what is the relation between any one of the three forces and the resultant of the other two forces? Any one of the three forces is the negative vector of the resultant of the of the other two forces meaning they possess the same magnitude but are opposite in direction and vice-versa.

3. If two forces with the same magnitude were exactly in the same opposite directions, what is the magnitude and direction of their resultant? What is the magnitude and direction of their equilibrant?

If two forces are equal and directly opposite, then they entirely cancel each other out. The result is zero force. In this case, the resultant and equilibrant are both zero. In other words, the resultant and equilibrant are the “zero vector.”

4. Use the component method to find the magnitude and direction of the ff. forces.
A. 2000 at 0o B. 1500 at 600 C. 1000 at 1500 D. 3800 at 225o

Resultant Force:

= √(-803.03117)2 + (-887.96766)2 =1197.22413 N O= tan-1 Ι-887.96766/-803.03117 = 47.90 ~ QIII= 47.90 +180 = 227.90