Static Equilibrium: Forces and Torques
RYERSON UNIVERSITY
DEPARTMENT OF PHYSICS
LAB REPORT
FOR
PCS 211 SECTION **
EXPERIMENT: STATIC EQUILIBRIUM - FORCES AND TORQUES
EXPERIMENTERS: ***** ********* ***** *********
AUTHORS OF THIS REPORT *** ***
EXPERIMENT PERFORMED ON: ***
REPORT SUBMITTED ON: ***
INSTRUCTOR: ***
PRE-LAB QUESTIONS:
1) What is meant by static equilibrium?
The meaning of static equilibrium can be explored by first examining the definition of equilibrium. Equilibrium means that an object is at rest or that the objects center of mass moves at constant velocity relative to the observer.
Static equilibrium is the case where an object is at rest. An object is at rest or at static equilibrium when the net force applied on it is zero. When an object is at rest about an axis it may have a tendency to rotate depending on the distribution of mass or if a force is applied. This tendency to rotate is called torque must also be equal to zero for the conditions of static equilibrium to be satisfied.
2) How do you define torque (or moment of a force)? Give the most general definition, illustrate with a diagram.
Force
Torque is the tendency of a force to rotate an object about an axis. Torque is defined as the product of the force applied perpendicularly to the surface of the affected object and the distance of that force from a point of pivot –
Torque = Force * Distance
Distance
Axis of rotation/Pivot
3) Can a body be in static equilibrium if subject to only one force? Explain briefly.
A body cannot be in static equilibrium if it is subject to only one force. When one force is applied the object will accelerate governed by the following equation:
F=m*a
If the object is in static equilibrium then it is also at rest and net forces acting on the object equal zero. This necessitates that there must be a counteracting force cancelling out the single original force that was applied to the object. Otherwise the
DEPARTMENT OF PHYSICS
LAB REPORT
FOR
PCS 211 SECTION **
EXPERIMENT: STATIC EQUILIBRIUM - FORCES AND TORQUES
EXPERIMENTERS: ***** ********* ***** *********
AUTHORS OF THIS REPORT *** ***
EXPERIMENT PERFORMED ON: ***
REPORT SUBMITTED ON: ***
INSTRUCTOR: ***
PRE-LAB QUESTIONS:
1) What is meant by static equilibrium?
The meaning of static equilibrium can be explored by first examining the definition of equilibrium. Equilibrium means that an object is at rest or that the objects center of mass moves at constant velocity relative to the observer.
Static equilibrium is the case where an object is at rest. An object is at rest or at static equilibrium when the net force applied on it is zero. When an object is at rest about an axis it may have a tendency to rotate depending on the distribution of mass or if a force is applied. This tendency to rotate is called torque must also be equal to zero for the conditions of static equilibrium to be satisfied.
2) How do you define torque (or moment of a force)? Give the most general definition, illustrate with a diagram.
Force
Torque is the tendency of a force to rotate an object about an axis. Torque is defined as the product of the force applied perpendicularly to the surface of the affected object and the distance of that force from a point of pivot –
Torque = Force * Distance
Distance
Axis of rotation/Pivot
3) Can a body be in static equilibrium if subject to only one force? Explain briefly.
A body cannot be in static equilibrium if it is subject to only one force. When one force is applied the object will accelerate governed by the following equation:
F=m*a
If the object is in static equilibrium then it is also at rest and net forces acting on the object equal zero. This necessitates that there must be a counteracting force cancelling out the single original force that was applied to the object. Otherwise the
References: Serway and Jewett. (2006). Physics: for scientists and engineers with modern physics 6E. California State Poly technic University – Pomona Tipler, Paul (2004). Physics for Scientists and Engineers: Mechanics, Oscillations and Waves, Thermodynamics (5th ed.). W. H. Freeman. ISBN 0-7167-0809-4.