Atwood's machine illustrates the effects of force in producing motion.

Atwood's Machine

Atwood's machine illustrates the effects of force in producing motion.

"Batering-ram, an engine for battering down the walls of besieged places. The ancients employed two different engines of this kind-- one suspended in a frame, the other movable on wheels or rollers. They consisted of a beam or spar with a massive metal head, and were in motion either by a direct application of manual force or by means of cords or pulleys." -Vaughan, 1906

Battering Ram

"Batering-ram, an engine for battering down the walls of besieged places. The ancients employed two…

"The force of the thrust is delivered principally with the right arm, the left being used to direct the bayonet. The points at which the attack should be directed are, in order of their importance, stomach, chest, head, neck, and limbs." — Moss, 1914

Bayonet thrust

"The force of the thrust is delivered principally with the right arm, the left being used to direct…

Uniting the theories of partial polygons of resistance and centres and lines of resistance, this buttress of blocks illustrates the tangential curve that is the line of pressures.

Buttress of Blocks

Uniting the theories of partial polygons of resistance and centres and lines of resistance, this buttress…

"The capstan, in universal use, on board of ships, is an axle placed upright, with a head, or drum, A, pierced with holes for the levers B, C, D. The weight is drawn by the rope E, passing two or three times round the axle to prevent its slipping. This is a very powerful and convenient machine. When not in use, the levers are taken out of their places and laid aside, and when great force is required two or three men can push at each lever." —Comstock, 1850

Capstan

"The capstan, in universal use, on board of ships, is an axle placed upright, with a head, or drum,…

This illustration shows rays attracted to a magnet, and exerting force upon the object against which they are striking.

Cathode

This illustration shows rays attracted to a magnet, and exerting force upon the object against which…

"When a vessel containing water is whirled rapidly round, why does not the water fall out when the vessel is upside down? Because the centrifugal force, tending to make the water fly from the center, overcomes or balances the attraction of gravitation, which tends to cause the water to fall out." — Wells, 1857

Centrifugal Force

"When a vessel containing water is whirled rapidly round, why does not the water fall out when the vessel…

"Suppose a cannon ball, tied with a string to the centre of a slab of smooth marble, and suppose an attempt be made to push this ball with the hand in the direction of b; it is obvious that the string would prevent its going to that point; but would keep it in thei circle. n this case, the string is the centripedal force." -Comstock 1850

Centrifugal Force

"Suppose a cannon ball, tied with a string to the centre of a slab of smooth marble, and suppose an…

"Attach a ball, for instance, to a cord; and , fastening the end of the cord at a point, O, give a quick impulse to the ball. It will be found to move in a circle, ABCD, because the cord keeps it within a certain distance of the centre (sic). Were it not for this, it would move in a straight line." —Quackenbos 1859

Centrifugal Force

"Attach a ball, for instance, to a cord; and , fastening the end of the cord at a point, O, give a quick…

"The instant one of the strings is let go, the centrifugal force carries off the stone in a tangent to the circle it was describing." —Quackenbos 1859

Centrifugal Force

"The instant one of the strings is let go, the centrifugal force carries off the stone in a tangent…

"AB is a wheel with a broad rim, or felly. A wine glass partly filled with water is placed on the inner surface of the felly, and the wheel is then made to revolve rapidly round the axle O. If the proper amount of motion be communicated to the wheel, not only will the wine glass keep its place on the felly, but the water also will remain in it..." —Quackenbos 1859

Centrifugal Force Demonstration

"AB is a wheel with a broad rim, or felly. A wine glass partly filled with water is placed on the inner…

"Where a motor is connected with the electric circuit of a dynamo...and the armature of the dynamo is rotated by mechanical power in opposition to the electromagnetic force, an electric current is generated, which tranverses the motor and causes its armature to rotate..." -Atkinson 1903

Connected dynamo and motor

"Where a motor is connected with the electric circuit of a dynamo...and the armature of the dynamo is…

This illustration shows the field between two equally and oppositely charged spheres, mapped out by lines of force.

Electricity

This illustration shows the field between two equally and oppositely charged spheres, mapped out by…

This illustration represents the field between two equal positive charges; in this case the lines of force do not pass from one to the other, but travel off to an infinate distance.

Electricity

This illustration represents the field between two equal positive charges; in this case the lines of…

This illustration shows the lines of force when a positive charge equal to 4 at A, and a negative charge of 1 at B, are used. A being numerically stronger than B, lines starting from A will not fall on B, but pass off to infinate distance.

Electricity

This illustration shows the lines of force when a positive charge equal to 4 at A, and a negative charge…

This illustration shows the field of force due to a charge 1 at A, and a like charge 4 at B.

Electricity

This illustration shows the field of force due to a charge 1 at A, and a like charge 4 at B.

This illustration shows the field of force between two parallel planes. At the edges its lines of foce curve out. Some pass from the back of one plane to the back of the other.

Electricity

This illustration shows the field of force between two parallel planes. At the edges its lines of foce…

A is a positively charged conductor and B represents the equal and oppsite charge. When the conductor C is introduced into the field, some of the lines of force are divided, since they cannot exist in a conductor.

Electricity

A is a positively charged conductor and B represents the equal and oppsite charge. When the conductor…

"When a charge is moved from any point to another point in the same equipotential surface, no work is done upon it. When a charge is moved from one such surface to another, the work done is independent of the path of transfer. If such a surface was to be rendered impenetrable, a particle could lie upon it without tendancy to move along it in any direction. If any two points in such a surface were to be joined by a conductor, no flow of electrification would take place. The closed lines are equipotential lines drawn, upon equipotential surfaces, about two similartly electrified spheres, the quantity of electrifaction at A being twice that at B." -Avery 1895

Equipotential Lines

"When a charge is moved from any point to another point in the same equipotential surface, no work is…

"If the conducting wire is bent into the form shown, the lines of force will pas around the wire from one face of the loop to the other, and in the direction indicated by the 'rule of thumb' just given." -Avery 1895

Magnetic Field Around a Current Carrying Wire

"If the conducting wire is bent into the form shown, the lines of force will pas around the wire from…

An example of the turning tendency of force.

Force

An example of the turning tendency of force.

"An inclined plane is a slope, or flat surface, making an angle with a horizontal line...the force acts parallel to the base." —Hallock 1905

Inclined Plane with the Force Acting Parallel to the Base

"An inclined plane is a slope, or flat surface, making an angle with a horizontal line...the force acts…

"An inclined plane is a slope, or flat surface, making an angle with a horizontal line...the force acts parallel to the plane." —Hallock 1905

Inclined Plane with the Force Acting Parallel to the Plane

"An inclined plane is a slope, or flat surface, making an angle with a horizontal line...the force acts…

"The operation of the force-pump is similar to that of the suction-pump. The outlet-valve generally opens from the cylinder, the piston being made solid." — Avery, 1895

Force pump

"The operation of the force-pump is similar to that of the suction-pump. The outlet-valve generally…

"The force-pump differs from others in having its piston solid, or without a valve, and also in having a side pipe with a valve opening outwards, through which the water is forced to any height required, or against any pressure that may oppose it." -Marshall

Steam-engine Force Pump

"The force-pump differs from others in having its piston solid, or without a valve, and also in having…

"If a body be fastened to a string and whirled, so as to give it a circular motion, there will be a pull on the string that will be greater or less according as the velocity increases or decreases... If the string were cut, the pulling force that drew it away from the straight line would be removed, and the body would then fly off at a tangent; that is, it would move in a straight line tangent to the circle, as shown in Fig. 9." —Hallock 1905

Centrifugal Force

"If a body be fastened to a string and whirled, so as to give it a circular motion, there will be a…

"In the forcing-pump atmospheric pressure plays but a small part. There is no valve in the piston c, but the water raised through the suction-pipe a, and the valve g, is forced by each depression of the piston up through the pipe e e, which is furnished with a valve to prevent the return of the fluid." — Wells, 1857

Forcing-Pump

"In the forcing-pump atmospheric pressure plays but a small part. There is no valve in the piston c,…

"Hero's Machine. The generation of steam from water by the application of heat, and the mechanical force produced by this means, appear to have been understood at a very remote period; but their application to machinery devoted to the purposes of locomotion, is a discovery of recent date. The ingenious contrivances of early discoverers were devoted to objects of minor importance, as those of raising water and propelling smoke upwards." —Comstock, 1850

Hero's Machine

"Hero's Machine. The generation of steam from water by the application of heat, and the mechanical force…

"An instrument called the hydrostatic bellows, also shows, in a striking manner, the great force of a small quantity of water, pressing in a perpendicular direction. This instrument consists of two boards, connected together with strong leather, in the manner of the common bellows. It is then furnished with a tube a, which communicated between the two boards. A person standing on the upper board may raise himself up by pouring water into the tube. If the tube holds an ounce of water, and has an area equal to a thousandth part of the area of the top of the bellows, one ounce of water in the tube will balance a thousand ounces placed on the bellows." —Comstock, 1850

Hydraulic Bellows

"An instrument called the hydrostatic bellows, also shows, in a striking manner, the great force of…

"The power required to force a given weight up an inclined plane, is in proportion to its height, and the length of its base, or in other words, the force must be in proportion to the rapidity of its inclination." -Comstock 1850'

Inlined Plane with Weight

"The power required to force a given weight up an inclined plane, is in proportion to its height, and…

"Lines of force of a charged sphere and a conductor under induction. The negative electrification on the end a of the cylinder indicates that an equal number of lines set out from that end." -Hawkins, 1917

Lines of Force under Induction

"Lines of force of a charged sphere and a conductor under induction. The negative electrification on…

"The object W to be lifted is called the weight; the force is represented by P; the point, or pivot, F is called the fulcrum." —Hallock 1905

Lever

"The object W to be lifted is called the weight; the force is represented by P; the point, or pivot,…

"The object W to be lifted is called the weight; the force is represented by P; the point, or pivot, F is called the fulcrum." —Hallock 1905

Lever

"The object W to be lifted is called the weight; the force is represented by P; the point, or pivot,…

"The object W to be lifted is called the weight; the force is represented by P; the point, or pivot, F is called the fulcrum." —Hallock 1905

Lever

"The object W to be lifted is called the weight; the force is represented by P; the point, or pivot,…

Illustration of a lever with fulcrum F. W represents the weight lifted, P is the force that does the lifting, D is the distance from the fulcrum to the point of application of the force, and d is the distance from the fulcrum to the point where the weight is attached. In all possible relations of the fulcrum, weight, and force the following proportion holds: P:W = d:D.

Lever and Fulcrum

Illustration of a lever with fulcrum F. W represents the weight lifted, P is the force that does the…

Illustration of a hammer being used as a lever. F represents the fulcrum.

Hammer Used as a Lever

Illustration of a hammer being used as a lever. F represents the fulcrum.

Illustration of an ordinary steel-yard being used as a lever. F represents the fulcrum. Weight P is used to balance weight W.

Steel-yard Used as a Lever

Illustration of an ordinary steel-yard being used as a lever. F represents the fulcrum. Weight P is…

"Lines of force of a circular loop. If a current flow through the loop in the direction indicated, the lines of force both inside and outside the loop, will cross the plane of the loop at right angles, and all those which cross the loop on the inside will pass through the plane in one direction...while all on the outside will return through the plane in the opposite direction." -Hawkins, 1917

Lines of Force

"Lines of force of a circular loop. If a current flow through the loop in the direction indicated, the…

"Lines of force in a circular loop. If the loop pass through a piece of cardboard at right angles to its plane, and the curent flow as indicated, the dotted lines on the cardboard will represent the direction of the lines of force in the plane of the cardboard." -Hawkins, 1917

Lines of Force

"Lines of force in a circular loop. If the loop pass through a piece of cardboard at right angles to…

"Tracing lines of force with a suspended magnet." -Hawkins, 1917

Tracing magnetic field lines

"Tracing lines of force with a suspended magnet." -Hawkins, 1917

"Experiment showing lines of force in the magnetic field surrounding a conductor carrying an electric current." -Hawkins, 1917

Magnetic Field

"Experiment showing lines of force in the magnetic field surrounding a conductor carrying an electric…

"Experiment illustrating the molecular theory of magnetism. Coarse steel filings are placed inside a small glass tube and the contents magnetized. It will be found that filing which at first had no definite arrangement will rearrange themselves under the influence of magnetic force, and assume symmetrical position, each one lying in line with, or parallel to its neighbor, as shown in the lower figure." -Hawkins, 1917

Magnetism

"Experiment illustrating the molecular theory of magnetism. Coarse steel filings are placed inside a…

"Illustrating Maxwell's 'corkscrew rule' for relative directions of current and lines of force...a current flow through the wire ab in the direction from a to b, the magnetic lines will encircle the wire in the direction of the curved arrow ro which shows the direction in which the corkscrew must be turned to advance in the direction of the arrow n." -Hawkins, 1917

Maxwell's Corkscrew Rule

"Illustrating Maxwell's 'corkscrew rule' for relative directions of current and lines of force...a current…

Illustration showing two points a and b to be in the same plane and parallel.

Motions Of 2 Points In Same Plane And Parallel

Illustration showing two points a and b to be in the same plane and parallel.

Illustration showing two points a and b to be in the same plane and parallel.

Motions Of 2 Points In Same Plane And Parallel

Illustration showing two points a and b to be in the same plane and parallel.

Illustration showing three points a, b, and c in motion. The magnitude and direction of a and b are used to find the l.v. of c.

Motions Of 3 Points

Illustration showing three points a, b, and c in motion. The magnitude and direction of a and b are…

Illustration used "If three component motions ab, ac, and ad are combined, their resultant af will be the diagonal of the parallelopiped of which they are the edges."

Parallelopiped of Motions

Illustration used "If three component motions ab, ac, and ad are combined, their resultant af will be…

"In the diagram, let AB and AC represent two forces acting upon the point, A. Draw the two dotted lines to complete the parallelogram." — Avery, 1895

Parallelogram

"In the diagram, let AB and AC represent two forces acting upon the point, A. Draw the two dotted lines…

"When the pendulum is drawn from its vertical position, the force of gravity, MG, is resolved into two components, one of which, MC, produces pressure at the point of support, while the other, MH, acts at right angles to it, producing motion toward N." -Avery 1895

Motion of a Pendulum

"When the pendulum is drawn from its vertical position, the force of gravity, MG, is resolved into two…

A pair of opposite poles attracting, the magnetic force shown by iron filings.

Attractive poles

A pair of opposite poles attracting, the magnetic force shown by iron filings.

Illustration of a hydraulic machine. "A principle known as Pascal's Law states that pressure exerted on a liquid in a closed vessel is transmitted equally and undiminished in all directions." If a, A, p, and P respectively represent the areas and pressures, then the following proportion holds: a:A = p:P.

Hydraulic Machine Exerting Pressure

Illustration of a hydraulic machine. "A principle known as Pascal's Law states that pressure exerted…

An experimental verification of the Principle of Archimedes.

Experimental Verification of Principle of Archimedes

An experimental verification of the Principle of Archimedes.

"This sublime tragedy was enacted about 460 B.C. All the characters in it are superhuman. The divine hero Prometheus has been doomed by Zeus to be chained to Mount Caucasus, in Scythia. This is his punishment for his benefactions to mankind, espeically the gift of fire, which he had stolen from heaven. The god Hephaestus, with his attendants, Strength and Force, execute the king's decree. The chained hero is visited by the god Oceanus and his daughters, who commiserate his fate." — The Delphian Society, 1913

Prometheus bound

"This sublime tragedy was enacted about 460 B.C. All the characters in it are superhuman. The divine…

"A double-acting pump of the piston pattern is shown [here]. Such a pump has two sets of suction valves and delivery valves, one set for each side of the piston. With the piston moving in the direction of the arrow, the pressure of the atmosphere forces the water up the suction pipe P into the left-hand end of the pump cylinder, the left-hand suction valve opens and the left-hand delivery valve is closed...The water now flows up the delivery pipe P'." —Hallock 1905

Double-acting Force Pump

"A double-acting pump of the piston pattern is shown [here]. Such a pump has two sets of suction valves…

An illustration of a force pump which is used to force liquid up and expel it under pressure.

Force Pump

An illustration of a force pump which is used to force liquid up and expel it under pressure.

"As the piston ascends, as shown in the left-hand figure, the pressure of the atmosphere forces the water up the suction pipe P; the water opens the suction valve V and flows into the pump cylinder. When the piston moves down, as shown in the right-hand figure, the suction valve is closed and the delivery valve V' opened. The water in the pump cylinder is now forced up the delivery pipe P'." —Hallock 1905

Forcing Pump

"As the piston ascends, as shown in the left-hand figure, the pressure of the atmosphere forces the…

One sort of pump once common worldwide was a hand-powered water pump over a water well where people could work it to extract water, before most houses had individual water supplies.

Hand Operated Pump

One sort of pump once common worldwide was a hand-powered water pump over a water well where people…

"The action does not differ in any way from that of the piston force pump. During the up stroke of the plunger, the suction valve is open and the delivery valve is closed; during the down stroke, the suction valve is closed and the delivery valve is open." —Hallock 1905

Plunger Pump

"The action does not differ in any way from that of the piston force pump. During the up stroke of the…

"Steam pumps are force pumps operated by steam acting on the piston of a steam engine directly connected to the pump, and in many cases cast with the pump. A section of a double-acting steam pump, showing the steam and water cylinders, with other details, is illustrated [here]." —Hallock 1905

Steam Pump

"Steam pumps are force pumps operated by steam acting on the piston of a steam engine directly connected…

"Let, for instance, the force used by the boatman be twice as great as that of the tide. Then by the time he would reach B, the tide would have carried his boat one-half of that distance, to D." —Quackenbos 1859

Resultant Motion with Boat

"Let, for instance, the force used by the boatman be twice as great as that of the tide. Then by the…