Case 1

Definition of torque

The tendency of a force to rotate an object about some axis.

Equipment

• Meter stick (1) - no metal ends

• Weight Hanger (1)

• Fulcrum (1)

• Mass Set (1)

• Clamps (4)

**Torque**

Torque(τ ) = r F sinϕ =Fd

F=

The applied force.

r=

is the distance between the rotation axis and the point of application of F.

d=

is the perpendicular distance from the rotation axis to the line of action of F.

θ=

is the angle between the force and the lever arm.

The( SI) unit of torque is a

N.m

Torque is a vector quantity.

The sign of torque is taken to be positive

(+)

if the force tends to produce counterclockwise rotation and negative

(-)

if the force tends to produce clockwise rotation about an axis.

Procedure

With the meter stick on the support stand, suspend a mass

m1= 100g

at the

3.5cm

mark on the meter stick. Then adjust the lever arm for a mass

m2= 200g

at the other end of the meter stick and adjust its position until the system is in static equilibrium. Using,

∑τ= 0

Result

Length of meter stick=

37cm

x0=

37/2 = 18.5cm

r1=

x0– x1

r2=

x2 – x0

% Difference =

100 (τcc - τcw) / [(τcc + τcw)/2]

Procedure

Place

m1= 200g

at the

15cm

from rotation center and Place an any mass m2 that safeties

τcc ˃ τcw

at other side of rotation center at same position.

Result

Case 3

Procedure

Place

m1= 150g

at the

14cm

from rotation center. Then place mass

m2 =150g

at any position that safeties

τcc ˃ τcw.

Result

Discussion

**Foundation of Biomechanics, BIOEN 312**

Conclusion

References

Haneefa Barnawi

Maha Al-Shammari Maram Alqarni

Zahrah Alali

Error causes:

Human Errors

The arm stability

The definition for torque as

M = Frsinϕ

holds true under

differing masses and distances

from point of rotation.

The angle of applied force wasn't considered.

1. JEWETT, J. W., SERWAY, R. A., & PEROOMIAN, V. (2010). Physics for scientists and engineers. Vol. 1 Vol. 1. [Pacific Grove], Brooks/Cole Cengage Learning.

2. KNIGHT, J., & SCHLAGER, N. (2002). Science of everyday things. Detroit, Gale Group.

3. LERNER, K. L., & LERNER, B. W. (2008). Gale encyclopedia of science. Detroit, Thomson Gale.

4. NORDIN, M., & ÖZKAYA, N. (2012). Fundamentals of biomechanics: equilibrium, motion, and deformation. New York [u.a.], Springer.

5. OKUNO, E., & FRATIN, L. (2014). Biomechanics of the human body. New York, Springer.

Aim

The aim of our experiment is to apply the principle of torque and to see how torque is affected by force and distance.