The General Physics ClipArt gallery offers 222 images showing principles of the science and proof of theorems. Physics is the science of basic concepts such as energy and force.

"This will be understood, when we consider that the reaction of b is just equal to the action of a, and that each of the other balls, in lke manner, ac, and react, o n the other, until the motion of a arrives at f, which, having no impediment, or nothing to act upon, is itself ut in motion." -Comstock 1850

Action and Reaction

"This will be understood, when we consider that the reaction of b is just equal to the action of a,…

"An instrument illustrating the expansive force of steam generated in a closed vessel, and escaping through a narrow aperture, said to have been invented by Hero of Alexandria in the second century B.C. "-Whitney, 1902

Aeolipile

"An instrument illustrating the expansive force of steam generated in a closed vessel, and escaping…

This apparatus represents the single barrel of the double-acting pump of Bianchi.

Air-pump

This apparatus represents the single barrel of the double-acting pump of Bianchi.

"The general scheme of Geisler's pump is shown here. A and B are pear-shaped glass vessels connected by a long narrow india-rubber tube, which must be sufficiently strong in the body (or strengthened by a linen coating) to stand an outward pressure of 1 to 1.5 atmospheres. A terminates below in a narrow vertical tube c, which is a few inched longer than the height of the barometer, and to the lower end of this tube the india-rubber tube is attached which connects A with B. To the upper end of A is soldered a glass two-way stop-cock, by turning which the vessel A can either be made to communicate through s and a hole in the hollow cock with the vessel to be exhausted." —The Encyclopedia Britannica, 1903

Air-Pump

"The general scheme of Geisler's pump is shown here. A and B are pear-shaped glass vessels connected…

"The general scheme of Geisler's pump is shown here. A and B are pear-shaped glass vessels connected by a long narrow india-rubber tube, which must be sufficiently strong in the body (or strengthened by a linen coating) to stand an outward pressure of 1 to 1.5 atmospheres. A terminates below in a narrow vertical tube c, which is a few inched longer than the height of the barometer, and to the lower end of this tube the india-rubber tube is attached which connects A with B. To the upper end of A is soldered a glass two-way stop-cock, by turning which the vessel A can either be made to communicate through s and a hole in the hollow cock with the vessel to be exhausted." —The Encyclopedia Britannica, 1903

Air-Pump

"The general scheme of Geisler's pump is shown here. A and B are pear-shaped glass vessels connected…

"This was invented in 1865 by H. Sprengel. The instrument, in its original (simplest) form, consists of a vertical capillary glass tube a of about 1 mm. bore, provided with a lateral branch b near its upper end, which latter, by an india-rubber join governable by a screw-clamp, communicates with a funnel. The lower end is bent into the shape of a hook, and dips into a pneumatic trough. The vessel to be exhausted is attached to b, and, in order to extract its gas contents, a properly regulated stream of mercury is allowed to fall through the vertical tube." —The Encyclopedia Britannica, 1903

Air-Pump

"This was invented in 1865 by H. Sprengel. The instrument, in its original (simplest) form, consists…

This barometer depends upon the changes in form of a think metallic vessel partially exhausted of air, as the atmospheric pressure varies.

Aneroid Barometer

This barometer depends upon the changes in form of a think metallic vessel partially exhausted of air,…

This figure represents an apparatus frequently employed for illustrating some of the consequences of Torricelli's Theorem.

Apparatus for verifying Torricelli's Theorem

This figure represents an apparatus frequently employed for illustrating some of the consequences of…

"A small portable force-pump."-Whitney, 1902

Aquapult

"A small portable force-pump."-Whitney, 1902

A simple apparatus called the arithmetical lever for illustrating the laws of parallel forces.

Composition of Parallel Forces

A simple apparatus called the arithmetical lever for illustrating the laws of parallel forces.

"Two cannon balls, when suspened by long cords, so as to hang quite near each other, are found to exert a mutual attaction, so that neither of the cords are excatly perpendicular, but they approach each other..." -Comstock 1850

Gravitational Attraction

"Two cannon balls, when suspened by long cords, so as to hang quite near each other, are found to exert…

All liquids that wet solids that are placed in them will be lifted, while those that don't will be pushed down. This is an example using mercury and water. b is a glass tube in water, c is a glass tube in mercury. The surface of the water in b is concave, while the surface of the mercury is convex.

Capillary Attraction

All liquids that wet solids that are placed in them will be lifted, while those that don't will be pushed…

"Atwood's Machine. This difficulty has however been overcome by a curious piece of machinery invented by Mr. Atwood. This consists of an upright pillar, with a wheel on the top. The weights A and B are of the same size and are made to balance each other, exactly, being connected by a thread passing over the wheel. The ring R admits the weight A, to fall through it in its passage to the stage S, on which it rests. The right and stage slide up and down, and are fastened by a thumb screw. The pillar is a graduated scale, and M is a small bent wire, weighing a quarter of an ounce, and longer than the diameter of the ring." —Comstock, 1850

Atwood's Machine

"Atwood's Machine. This difficulty has however been overcome by a curious piece of machinery invented…

"Machine designed by Atwood to allow the measurement and calculation of the velocities of falling bodies at various points accurately and easily." —Quackenbos 1859

Atwood's Machine

"Machine designed by Atwood to allow the measurement and calculation of the velocities of falling bodies…

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.

This experiment illustrates the law of action and reaction, which asserts that momentum cannot be imparted to any body without equal and opposite momentum being imparted to some other body.

Backward Movement of Discharging Vessel

This experiment illustrates the law of action and reaction, which asserts that momentum cannot be imparted…

In the common balance there is a stiff piece of metal called the beam, which turns about the sharp edge of a steel wedge forming part of the beam. The scale pans rest upon the hooks of the wedges.

Balance

In the common balance there is a stiff piece of metal called the beam, which turns about the sharp edge…

A balance of great delicacy with the glass case that contains it.

Balance for Purposes of Accuracy

A balance of great delicacy with the glass case that contains it.

The stability of the "balancer" depends on the fact that, owing to the weight of the two leaden balls, the center of gravity of the whole is below the point of support.

Balancer Toy Illustration

The stability of the "balancer" depends on the fact that, owing to the weight of the two leaden balls,…

An instrument used for indicating changes in atmospheric pressure.

Baroscope

An instrument used for indicating changes in atmospheric pressure.

"When the load is uniformly distributed on a beam of any cross-section, it will sustain a load twice as great as when the load is applied in the middle between the supports." — Hallock, 1905

Beam Strength

"When the load is uniformly distributed on a beam of any cross-section, it will sustain a load twice…

"The maximum safe load in pounds that any cylindrical beam is capable of sustaining at the middle when its ends merely rest upon supports, is equal to four times the cube of its diameter multiplied by .6 of the constant given in the table, and the product divided by the distance between its supports in feet." —Hallock 1905

Cylindrical Beam

"The maximum safe load in pounds that any cylindrical beam is capable of sustaining at the middle when…

A general view of the air-pump apparatus formed by Bianchi.

Bianchi's Air-pump

A general view of the air-pump apparatus formed by Bianchi.

Image of a locomotive from the front. E is the exhaust pipe, and S is the smokestack. T are tubes through which hot gases are expelled.

Locomotive Blast

Image of a locomotive from the front. E is the exhaust pipe, and S is the smokestack. T are tubes through…

If a lead ball and a piece of paper are placed into a glass tube in which all the air has been exhausted, then when the tube is inverted, both the ball and the piece of paper will fall at exactly the same time.

Falling Bodies

If a lead ball and a piece of paper are placed into a glass tube in which all the air has been exhausted,…

This apparatus is used to prove Boyle's Law which describes the relationship between the product pressure and volume within a closed system as constant when temperature remains at a fixed measure; both entities remain inversely proportional.

Proof of Boyle's Law for Expanding Air

This apparatus is used to prove Boyle's Law which describes the relationship between the product pressure…

"An air thermometer consists essentially of a large glass bulb at the upper end of a tube of small but uniform bore, the lower end of which dips into colored water." — Avery, 1895

Glass bulb

"An air thermometer consists essentially of a large glass bulb at the upper end of a tube of small but…

Buoyancy chambers, hydrostatic principle. Illustration of an unsuccessful scheme for a perpetual-motion device.

Buoyancy Chambers

Buoyancy chambers, hydrostatic principle. Illustration of an unsuccessful scheme for a perpetual-motion…

A glass cylinder is open at the bottom, having a piece of bladder or thin indian-rubber tightly stretched over the top.

Burst Bladder

A glass cylinder is open at the bottom, having a piece of bladder or thin indian-rubber tightly stretched…

"A cantilever is a beam, bar, rod, etc., fixed at one end and subjected to a transverse stress. It has a tendency to overthrow the wall or structure to which it is attached." — Hallock, 1905

Cantilever

"A cantilever is a beam, bar, rod, etc., fixed at one end and subjected to a transverse stress. It has…

"When the load is uniformly distributed on a cantilever of any cross-section, it will sustain a load twice as great as when the load is applied at one end." — Hallock, 1905

Cantilever

"When the load is uniformly distributed on a cantilever of any cross-section, it will sustain a load…

A rectangular cantilever with supports on the end and the load on the middle.

Cantilever

A rectangular cantilever with supports on the end and the load on the middle.

"The maximum safe load in pounds that should be allowed at the end of any cylindrical cantilever is equal to the cube of its diameter in inches multiplied by .6 of the constant given in the tale, and the product divided by its length in feet." —Hallock 1905

Cylindrical Cantilever

"The maximum safe load in pounds that should be allowed at the end of any cylindrical cantilever is…

Capillarity. On the left, water is higher in the smaller tubes due to adhesion. On the right, mercury has the opposite effect because of its cohesive properties.

Capillarity

Capillarity. On the left, water is higher in the smaller tubes due to adhesion. On the right, mercury…

A Cartesian diver or Cartesian devil is a classic science experiment, named for René Descartes, which demonstrates the principle of buoyancy and the ideal gas law.

Cartesian Diver

A Cartesian diver or Cartesian devil is a classic science experiment, named for René Descartes,…

"Why does a person carrying a weight upon his back stoop forward? In order to bring the center of gravity of his body and the load over his feet. If held in this position, he would fall backwards, as the direction of the center of gravity would fall beyond his heels." — Wells, 1857

Center of Gravity

"Why does a person carrying a weight upon his back stoop forward? In order to bring the center of gravity…

"Why does a person carrying a weight upon his back stoop forward? In order to bring the center of gravity of his body and the load over his feet, he assumes this position." — Wells, 1857

Center of Gravity

"Why does a person carrying a weight upon his back stoop forward? In order to bring the center of gravity…

"The center of gravity, in any body or system of bodies is that point upon which the body, or system of bodies, acted upn only by gravity will balance itself in all positions." -Comstock 1850

Center of Gravity

"The center of gravity, in any body or system of bodies is that point upon which the body, or system…

"But if one of the balls be heavier than the other, then the centre of gravity will, in proportion, approach the larger ball." -Comstock 1850

Center of Gravity

"But if one of the balls be heavier than the other, then the centre of gravity will, in proportion,…

"In a body of equal thickness, as a board, or a slab of marble, but otherwise of an irregular shape, the centre of gravity may be found by suspending it, first from one point, and then from another, and marking, by means of a plumb line, the perpendicular ranges from the point of suspension. the centre of gravity will be the point where these two lines cross each other." -Comstock 1850

Center of Gravity

"In a body of equal thickness, as a board, or a slab of marble, but otherwise of an irregular shape,…

"If w and W, fig. 3, be two bodies of known weight, their center of gravity will be at C." —Hallock 1905

Center of Gravity

"If w and W, fig. 3, be two bodies of known weight, their center of gravity will be at C." —Hallock…

"The part of the body in which the centre of gravity is situated, may be found, in some cases, by balancing it on a point. Thus the centre of gravity of the poker represented [here] lies directly over the point on which it is balanced." —Quackenbos 1859

Center of Gravity

"The part of the body in which the centre of gravity is situated, may be found, in some cases, by balancing…

"When such a surface is irregular in shape, suspend it at any point, so that it may move freely, and when it has come to rest, drop a plumb line from the point of suspension and mark its direction on the surface. Do the same at any other point, and the centre of gravity will lie where the two line intersect." —Quackenbos 1859

Center of Gravity

"When such a surface is irregular in shape, suspend it at any point, so that it may move freely, and…

"Where five blocks are placed in this position, the point of gravity is near the centre of the thrd block, and is within the base as shown by the plumb line. But on adding another block, the gravitation point falls beyond the base, and the whole will now fall by its own weight." -Comstock 1850

Center of Gravity of Standing Blocks

"Where five blocks are placed in this position, the point of gravity is near the centre of the thrd…

"Find the center of gravity of two of the bodies, as W1, and W4, in fig 4. Assume that the weight of both bodies is concentrated at C1, and find the center of gravity of this combined weight at C1, and the weight of W2; let it be at C2; then find the center of gravity of the combined weights of W1, W4, W2 (concentrated at C2), and W2; let it be at C; then C will be the center of gravity of the four bodies." —Hallock 1905

Compound Center of Gravity

"Find the center of gravity of two of the bodies, as W1, and W4, in fig 4. Assume that the weight of…

"A load of hay...upsets where one wheel rises by little above the other, because it is broader on the top than the distance of the wheels from each other; while a load of stone is very rarely turned over..." -Comstock 1850

Center of Gravity of a Load of Hay

"A load of hay...upsets where one wheel rises by little above the other, because it is broader on the…

"To find the center of gravity of any irregular plane figure, but of uniform thickness throughout, divide one of the parallel surfaces into triangles, parallelograms, circles, ellipses, etc., according to the shape of the figure; find the area and center of gravity of each part separately, and combine the center of gravity thus found in the same manner." —Hallock 1905

Center of Gravity of an Irregular Plane

"To find the center of gravity of any irregular plane figure, but of uniform thickness throughout, divide…

"When a line of direction falls within the base, a body stands when not, it falls... On the same principle, a load of stone may pass safely over a hillside, on which a load of hay would be overturned [as shown by the line of direction in this illustration]." —Quackenbos 1859

Line of Direction from the Center of Gravity of an Object

"When a line of direction falls within the base, a body stands when not, it falls... On the same principle,…

"When two bodies of equal weight are connected by a rod, the centre of gravity will lie in the middle of that rod. When two bodies of unequal weight are so connected, the centre of gravity will be nearer to the heavier one. These principles are illustrated [here], in which C represents the centre of gravity." —Quackenbos 1859

Center of Gravity of Rod with Weights

"When two bodies of equal weight are connected by a rod, the centre of gravity will lie in the middle…

"When a ball is rolling on a horizontal plane, the centre of gravity is not raised, but moves in a straight line, parallel to the surface of the plane on which it rolls, and is consequently always directly over its centre of gravity." -Comstock 1850

Center of Gravity of a Rolling Ball

"When a ball is rolling on a horizontal plane, the centre of gravity is not raised, but moves in a straight…

"If the plane is inclined downwards, the ball is instantly thrown into motion, because the centre of gravity then falls forward of that motion, or the point on which the ball rests." -Comstock 1850

Center of Gravity of a Ball Rolling on an Incline

"If the plane is inclined downwards, the ball is instantly thrown into motion, because the centre of…

"In a body free to move, the center of gravity will lie in a vertical plumb-line drawn through the point of support. Therefore, to find the position of the center of gravity of an irregular solid, as the crank, Fig 8, suspended it at some point, as B, so that it will move freely. Drop a plumb line from the point of suspension and mark its direction. Suspend the body at another point, as A, and repeat the process. The intersection C of the two lines will be directly over the center of gravity." —Hallock 1905

Center of Gravity of a Solid

"In a body free to move, the center of gravity will lie in a vertical plumb-line drawn through the point…

"But, suppose the same bar or iron, whose inertia was overcome by raising the centre, to have balls of different weights attached to its ends; then the centre of inertia would no longer remain in the middle of the bar, but would be changed to the point A..." -Comstock 1850

Center of Inertia

"But, suppose the same bar or iron, whose inertia was overcome by raising the centre, to have balls…

"A body's center of mass is the point about which all matter composing the body may be balanced. It is also called the center of inertia. In some cases, this is also the center of gravity." -Avery 1895

Center of Mass

"A body's center of mass is the point about which all matter composing the body may be balanced. It…

"Let any irregularly shpaed body, as a stone or chair, be suspended so as to move freely. Drop a plumb line from the point of the suspendsion, and make it fast or mark its direction. The center of mass will lie in this line. From a second point, not in the line already determined, suspend the body; let it fall a plumb line as before. The center of mass will lie in this line also. But to lie in both lines, it must lie at their intersection." -Avery 1895

Finding the Center of Mass

"Let any irregularly shpaed body, as a stone or chair, be suspended so as to move freely. Drop a plumb…

"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…