Force Table Apparatus: Engineering Mechanics Laboratory Manual Experiment#1

 

ENGINEERING MECHANICS EXPERIMENT NO.1

OBJECTIVE:

 To determine the resultant of forces in equilibrium.

APPARATUS:

 Force table (table, ring, string and four 50g hangers), set of slotted weights, protractor and ruler.

                                                 

 

               

                                           

              Figure 1.1: Force(Vector) Table Apparatus

THEORY:

The force table is an apparatus that allows the experimental determination of the resultant force produced by a combination of forces. The rim of the circular table is calibrated in degrees. Weight forces are applied to a central ring by means of strings running over pulleys and attached to mass hangers. Adding or removing slotted masses varies the magnitude of a force and changing the angle of the pulley varies the direction. Each pulley with its suspended mass represents a vector.

               

 PROCEDURE:

1.      Balance the tripod in the horizontal plane with the help of screw provided on the legs.

2.      Adjust the two pulleys in the horizontal plane at angle 01 and 02. Fixed any value of 01 and 02 between, 0⁰ and 360⁰. Measure angles between 01 and 02 with the help of protractor provided on the plate.

3.      Hang the weights by passing string over the pulleys. Place a reasonable value of force F₁ and force F₂ and observe the change in the position of the ring.

4.      Analytically find the magnitude and direction of the resulting force of F₁ and F₂ by using Parallelogram method or component method.

5.      Apply the calculated resultant force F_R having the same magnitude but in opposite direction on the pulley. Now observe the change in position of the ring.

6.      Repeat steps 1 and 5 with different values of 01 and 02.

OBSERVATIONS:

					Analytical Result		Practical Result		Percentage Error(%)
S.NO.	F1	θ1	F2	θ2	FR	θR	FR	θR	FR	θR

 

CALCULATIONS:

•      Use the method of Parallelogram method to find the magnitude and direction of the resultant force.

•      Plot graph between Resultant Force F_R on y-axis and its angle θ on x-axis `of analytical and practical results to show comparison graphically between them using Microsoft Excel.

PRECAUTIONS:

1.      The table along which the ring and string arrangement is placed should be horizontal.

2.      Pulleys should be frictionless.

3.      The self-weight of pulleys should be negligible in comparison to the weight/force used in the experiment.

4.      The ropes/strings used should be non-tensile/inelastic.

CONCLUSION:

Discuss the effect of the angle on the resultant force.