Vectors Practicum I

Goal:The purpose of this practicum is to gain experience in adding vector quantities experimentally, graphically, and computationally.

.BA FF

and forces two

of effects the adding were weSuppose

AF BF

BA FF

BA FFforcenetF

In this case the net force could also be called a resultant force, the one force that has the same effect on a body as the vector sum of two or more other forces.

Vectors Practicum I

AF BF

EF

0F

What if we instead wanted to determine the one force that would balance out the first two forces?

0 BAE FFF

BAE FFF

ntEquilibriaFE

Where

Equilibriant – the one force that balances one or more other forces and thereby results in an object in equilibrium

(Equilibrium occurs when the vector sum of the forces is zero)

Notice that the equilibriant is the same size but in the opposite direction of the

resultant!

Vectors Practicum I

For each case, hang the given masses at the stated angles. Be sure to include the mass hanger (m = 5.0 g = 0.0050 kg) in the total mass.

All directions are measured using counter-clockwise from 0° notation.

Adjust the pulleys downward until the strings are close to but not touching the top surface of the force table.

Vectors Practicum I

By trial and error, find the angle for the third super pulley clamp and the mass that must be suspended over the pulley so that its weight will act as the equilibriant and balance the forces exerted on the strings by the other two masses. Record as the Experimental Equilibriant.

Remember that the resultant must be the same size as the equilibriant, but in the opposite direction. Record the Expermental Resultant.

Vectors Practicum I

Experimental Method of Finding Equilibrium

The knot should be centered over the hole in the middle of the center post when the system is in equilibrium.

The anchor string should be slack.

Pull the knot slightly to one side and let it go. Check to see that the knot returns to the center. If not, adjust the mass and/or the angle of the super pulley clamp until the knot always returns to the center when pulled slightly to one side.

Vectors Practicum I

Compute the resultant both computationally and graphically (chose a scale). Record the results and calculate the percent error for each compared to the experimental value. Everyone should complete the worksheet, with one set for the group to be turned in at the end of the hour. PSYW

100% lTheoretica

alExperimentlTheoreticaError