natural sciences
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newtonian mechanics

  1. Units and Kinematics
    • Mass Measurement Sets of calibrated metric and imperial masses. (s/m) (T) *
    • Length Measurement Standard meter sticks and selection of cubic volumes. (m) (T) *
    • Time Measurement Time signals from U.S. Naval Observatory. (m) (T) *
    • Galileo's Chandelier Bowling ball pendulum with burning candles stuck in holes, used as prop only. (l) (T+) *
    • Density Aluminum/Uranium and SF6/Air/Helium comparisons. (m) (T) *
    • High Road, Low Road Which road is faster? A kinematics concept Puzzler. (l) (T+)
    • Scantling and Ball Ball rolling down tilted trough in oscillatory fashion yields acceleration (also known as Galileo's Inclined Plane) (m) (T) ***
    • Uniform Acceleration Glider acceleration by an inclined air track or by a falling weight/string attachment; large ballbearing rolling on PASCO track (with strings). (l) (T+)
  2. Vectors and Forces in Equilibrium (Statics)
    • Vector Arrows Wooden arrow vectors, hand held or mountable. (m) (T) *
    • Train on Circular Track Vector representation of position, velocity, and acceleration. (m) (T) *
    • Tension Puzzler Two weights tugging on a spring balance; to what result?
    • Vector Sum of Forces Magnetic blackboard mechanics with spring balances and weights. (m) (T) **
    • Center of Mass Several irregular laminae with plumb bob. (m) (T+)
    • Stack of Blocks A dozen blocks are stacked on top of each other over the edge of the table seemingly defying gravity. (m) (T) ***
    • Loaded Beam Beam supported at ends with platform scales and toy truck as load to demonstrate moment arms. (m) (T+) **
    • Three-Legged Table Triangular table supported by platform scales. (l) (T) *
    • Leaning Ladder Small ladder against wall with variable load and inclination. (m) (T) **
    • Friction Blocks Selection of blocks that slide down a variable-angle inclined plane to demonstrate the various aspects of friction. (m) (T) *
    • Fakir Physics The concept of pressure is demonstrated by lying on a bed of nails. (m) (T) ***
  3. Simple Machines
    • Levers Lever types using bars and objects or blackboard mechanics set. (m) (T)
    • Jaw Models Cardboard animal jaws as examples of levers. (m) (T) *
    • Screw Jack An example of a cylindrical wedge to show mechanical advantage. (m) (T)
    • Winch An application of a lever arm to show mechanical advantage. (m) (T)
    • Hydraulic Press Application of Pascal's Principle to bend metal or break 2x4's. (m) (T)
    • Pulley Board Upright board or Blackboard Mechanics with pulley combinations. (m) (T)
    • Bosun's Chair Block and tackle, or a simple pulley, attached to hall ceiling for lecturer to hoist self. (l) (T++)
  4. Newton's First Law
    • Inertia of Rest Concrete block smashed on lecturer's chest with sledge hammer. (m) (T)
    • Dinner Table Sliding tablecloth out from under posh dinner setting. (m) (T+) ***
    • Diving Egg Trick Egg plunges into glass upon lateral removal of pie tin by broom. (m) (T+)
    • Penny Catch A row of 10 or 20 pennies are laid on your forearm - swing your arm forward and catch all the pennies in midair! (m) (T)
    • Uniform Motion Large ballbearing rolling on long PASCO track. (l) (T+)
    • Friction Blocks Demonstrate that kinetic friction does not depend on surface area but does depend on the normal force. (m) (T+)
    • Locked Brakes The difference between static and kinetic friction can cause the car to skid when braking. (m) (T+)
    • Air Table Center-of-Mass Motion Coupled masses on air table. (l) (T+)
    • Air Track Center-of-Mass Motion Push-me/pull-me gliders or pendulum glider on air track. (l) (T+)
    • Irregular Lamina Motion Irregular lamina with marked center-of-mass tossed in air. (m) (T)
    • Magic Marker Center-of-Mass Motion Markers attached to an irregular lamina record the motion of various points, including the COM. (m) (T+)
  5. Newton's Second Law and Gravity
    • Scantling and Ball Ball rolling down tilted trough in oscillatory fashion yields acceleration (also known as Galileo's Inclined Plane). (m) (T) ***
    • Uniform Acceleration Glider acceleration by an inclined air track or by a falling weight/string attachment; large ballbearing rolling on PASCO track (with strings). (l) (T+)
    • Atwood's Machine Combinations of weights suspended over pulley to show that asymmetry causes acceleration. (m) (T+)
    • Double Atwood Machine Prediction of motion of mass in a more complex wheel, axle, and pulley assembly. (m) (T+)
    • Brachistochrone Straight and cycloidal inclined paths, with the ball on the cycloidal path always beating the straight to the bottom. (m) (T)
    • Ball and Strobe A ball is dropped 5 meters and photographed under stroboscopic illumination. (l) (T++)
    • Newton's Apple Apple electronically released from platform; fall time given by special circuit and digital display. (l) (T++) ****
    • Resistance to Free Fall Ping-pong balls are dropped in air and CO2 for comparison. (m) (T+)
    • Nutty Free Fall Large nuts linked by threads at different distances (d, 4d, 9d, 16d, 25d, etc.) dropped from platform; sound of landing gives equal time intervals. (l) (T+)
    • Falling Faster than 'g' Relation between angular acceleration and linear acceleration to give free-fall paradox. (m) (T)
    • Feather and Dime Falling in an evacuated tube at the same rate. (l) (T+)**
    • Drop-n-Catch Ball drops from mast of PASCO cart; its motion can be considered relative to the moving cart or the track frame of reference. (l) (T+)
    • Shoot-n-Drop Ball shot horizontally, one dropped vertically; both hit the ground at the same time. (s) (T+) **
    • Shoot-n-Catch Ball shot up from PASCO cart is caught by same; a puzzler to ponder if track is tilted and cart accelerates down (or decelerates up). (l) (T++)
    • Shoot the Monkey Monkey released from platform is shot by simultaneously fired cannon. (l) (T++) ****
    • Reversible (Kater's) Pendulum A physical pendulum with two adjustable knife edges for an accurate determination of "g". (m) (T) **
    • Cavendish Experiment Calculation of gravitational constant, with accompanying apparatus model. (l) (T++) ****
    • Potential Well Orbital motion simulated by ball rolling on wooden potential well. (m) (T) *
  6. Newton's Third Law
    • Reaction Carts/Gliders Twin back-to-back spring loaded carts on track or gliders on airtrack. (l) (T+)
    • Reactionary Roadbed Radio controlled car moves on way while road moves the other. (l) (T+) **
    • Sailboat Reaction Cart A motorized fan mounted on a reaction cart blows air into a "sail" which is also mounted on the cart. Which way will the cart move? (m) (T)
    • Train on Circular Track Train moves one way, track moves the other. (l) (T+)
    • Air/Water Rocket The choice of propellant for this toy rocket makes a huge difference in thrust. (m) (T)
    • Rocket Car Single seat CO2 powered rocket cars. (l) (T+)
    • Cannon Recoil Gunpowder cannon mounted on rails. (l) (T++)
    • Hero's Engine A Cylindrical boiler with tangential steam jets spins on its axis. (m) (T+)
    • Inverse Sprinkler Which direction does a lawn sprinkler spin if water enters the nozzle, rather than being expelled from the nozzle? (m) (T)
    • Repulsive Symmetry A pair of horseshoe magnets symmetrically repel each other as observed on OHP. (s) (T)
  7. Impulse, Work, and Energy
    • Egg Throw Students are invited to throw a raw egg as hard as they please. The egg does not break when caught in a sheet. (l) (T+)
    • Karate Blow The instructor breaks several boards with a swift blow of the hand. (m) (T+) ****
    • Pencil Blow Gun A blow gun shoots a pencil through a board. (l) (T++)
    • Toilet Paper Toilet paper is torn off a roll by a quick yank but not by a slow pull. (m) (T) *
    • Marginal String A weight is suspended by a marginally strong string. Pulling on the weight with a similar string breaks the former, depending on the impulse. (m) (T)
    • Pile Driver A falling weight drives a nail through a board. (m) (T)
    • Gravi Car A falling weight propels a car forward. (l) (T+) **
    • Wind-Up Truck A wound-up spring propels a toy truck. (m) (T)
  8. Conservation of Linear Momentum and Energy
    • Happy and Unhappy Balls An amusing example of elastic and inelastic collisions. Also a momentum change / impulse puzzler. (m) (T)
    • Elastic and Inelastic Collision Model Two carts collide with a wall.
    • Elastic and Inelastic Collisions Gliders on airtrack; pucks on air table. (l) (T+)
    • Reactionary Roadbed Radio controlled car moves one way while road moves the other. (l) (T+) **
    • Newton's Cradle Conservation of momentum in elastic collisions between suspended spheres. (s) (T) **
    • Bouncing Collision A tennis ball/basketball combination is dropped to the floor ... the tennis ball theoretically bounces to nine times the original drop height. (m) (T)
    • Special Bouncing Collisions Same as previous except that mass ratio of balls is 1:3 (softball:basketball) leaving basketball dead and softball four times the height. (m) (T)
    • Two Dimensional Collisions Elastic collisions between steel balls. (m) (T+)
    • Pool Table Requiring little or no skill and the aid of a carpenter's square, one shot sinks two balls into the pockets. (l) (T+) ***
    • Killer Shuffleboard Elastic collisions between large iron pucks. (l) (T)
    • Pendulum and Nose Faith in the conservation of energy is tested by taking the demonstrator's nose to task. (l) (T+) ***
    • Egg Psych-Out More physics in your face with a heavy mass and spring over a carton of eggs (or your face). (l) (T++)
    • Crashing Pendulum A pendulum is allowed to "crash" into a bar, dramatically altering its motion, but energy is conserved as is evidenced by the return swing. (m/l) (T/T+)
    • Loop-the-Loop A toy car rolling down a loop-the-loop track demonstrates the minimum height it must start at to successfully negotiate the loop. (m) (T+) ***
    • Mass and Spring Potential and kinetic energy tradeoffs exhibited by a bouncing mass on the end of a spring. (m) (T)
    • Bottle Game Try to knock the bottle over on the return swing! (m) (T)
    • Bow and Arrow Shoot Use conservation of energy to predict the height the arrow will reach. (l) (T++)
  9. Angular Momentum
    • Three Dumbbells Lecturer rotates on turntable whilst holding two dumbbells. (l) (T) ***
    • Orbiter Ball on string orbits with increasing speed as string is shortened. (m) (T) **
    • Coffee Mug on a String Drop your favorite mug and have it saved in the nick of time by an orbiting pen. (m) (T)
    • Flyball Governor Rotating balls change speed as radius of rotation is changed. (m) (T)
    • Train on Circular Track Train moves one way, track moves the other. (l) (T+)
    • Tail Wags Dog Lecturer tries to swing baseball bat while standing on turntable. (m) (T)
    • Child's Top A stage prop to be used in discussion of angular momentum. (m) (T)
    • Maxwell's Top A top whose pivot coincides with its center of gravity so that there are no gravitational torques. (s) (T)
    • Gyroscope Small gyroscope used primarily as a stage prop in discussion. (s) (T)
    • Counter-balanced Gyro Gyro (mounted in gimbal) with movable weight to balance the top or to apply torque to cause precession. (m) (T)
    • Bicycle Wheel Gyro Same as counter-balanced gyro but physically large. (l) (T)
    • Angular Momentum Bicycle Wheel Hand-held version to be used with turntable for addition/subtraction of angular momentum; can also be suspended by handle from a rope for precession. (m/l) (T)
    • Ship Stabilizer Gyro Side to side rocking of a model boat is damped by a gyro. (m) (T)
    • Suitcase Gyro A motor driven gyro hidden in a suitcase gives surprising results when the suitcase is moved. (m) (T)
    • Dueling Gyros Two motor driven gyros turn in the opposite or same direction to add or cancel angular momenta. (m) *T)
    • Air Gyro Air supported ball shows all the salient features of gyroscopic motion. (m) (T+)
  10. Rotational Dynamics (moment of inertia and the action of torques)
    • Angular Impulse Wheel is made to rotate by falling weight attached by string. (m) (T)
    • Tippy-Top A top that flips upside down raising its center of gravity and reverses spin. (s/m) (T)
    • Rattleback This object, when given a spin, seems to defy the laws of angular momentum as it stops spinning, rocks in place, and proceeds to spin in the opposite direction. (s) (T+)
    • Rotational Stability A chain or rope (lariat), when rotated fast enough, assumes an axis about which its moment of inertia is maximum. (m) (T)
    • Spinning Football/Coconut Preferred axis of rotation for stability. (m) (T)
    • Tennis Racquet Flip Demonstration of stable and unstable axes of rotation. (m) (T)
    • Torsion Pendulum Determination of the moment of inertia by period measurements. (m) (T+)
    • Yo-yo A very large cable spool (or smaller version) is made to roll in either direction or slide, depending on the angle of pull; action of a torque. (l) (T) **
    • Which Way Will the Bike Move? A puzzler concerning torques - pull on a rope attached to the pedal and figure out the consequences. (m) (T)
    • Inclined Plane Various disks are raced down an inclined plane to verify the effect of their moments of inertia. (l) (T+)
    • Rotating Rod A rod with adjustable weights (moment of inertia) is made to rotate by a falling weight attached to the axle via string (m) (T)
    • Center of Percussion The motion (or lack of motion) of the suspension point of an object is observed when the object is struck a blow. (m) (T+) **
    • Breaking Broomstick on Wineglasses Two wineglasses support a broomstick which is given a swift blow with a pipe. The broomstick, but not the glasses, breaks. (m) (T+)
    • Falling Faster than 'g' Relation between angular acceleration and linear acceleration to give free-fall paradox. (m) (T)
  11. Rotational Dynamics (centripetal forces and rotating reference frames)
    • Tennis Ball on a String Whirl it around and then let go. (m) (T)
    • Loop-the-Loop A toy car rolling down a loop-the-loop track demonstrates the minimum height it must start at to successfully negotiate the loop (m) (T+) ***
    • Barrel of Fun Turntable model of amusement park ride to investigate angular velocities necessary to keep objects pinned to wall. (l) (T+) **
    • Bucket of Water A bucket, partially filled with water, is swung in a vertical circle at arms length without spilling a drop. (m) (T) **
    • Olive-Wineglass Puzzler The trick is to pick up an olive with an inverted wineglass and transfer it to another. (s/m) (T+)
    • Motor Driven Turntable A row of weights, aligned on the radius of the turntable, come flying off as rate of rotation is increased. (l) (T+)
    • Centripetal Force Puzzler Tethered, floating balls move radially inward on rotating turntable, contrary to intuition; also done with candle flame. (s/m) (T)
    • Coriolis Force Students try to throw a volley ball to each other or into a basket while sitting on a rotating platform; lots of fun (xl) (T+) ***
    • Foucault Pendulum Is the pendulum rotating? Presently available only in hall D. (l) (T+++) **
  12. Pressure
    • Mercury Barometer Column of mercury in glass tube, supported by atmosphere. (m) (T++)
    • Pascal Vases Pressure at the bottom of a vessel is proportional to the depth of the liquid and independent of the volume and shape of vessel. (s) (T+) **
    • Pascal's Paradox Vessels with identical bases are filled to the same level and placed on a platform scale; scale measures force = area (same) x pressure (same). (m) (T) **
    • Pressure and Depth Cylinder with water spouts at different depths. (m) (T+)
    • Magdeburg Hemispheres When evacuated, held together by atmospheric pressure; takes football team to separate them. (m) (T+) ***
    • 55 Gallon Drum Drum evacuated by vacuum pump; crushed by atmospheric pressure. (l) (T+) ***
    • Coke Can A coke can with hot water vapor inside implodes dramatically upon touching cold water. (m) (T)
    • Golf Ball Atmosphere Demonstration of molecular motion and pressure using golf balls. (l) (T) ***
    • Blow-Up Balloon in Vacuum A sealed balloon in a bell-jar "blows up" as the jar is evacuated. (m) (T+)
    • Vacuum Cannon Air rushing into an evacuated tube pushes a ball down the tub with such a force and speed that it "blasts out" the other end. (m) (T)
    • Water Bottle and Lead Bricks Adding a small volume of water to a hydrostatic head connected to a water bottle raises lead bricks. (l) (T+)
    • Siphon Transfer of water from one tank to another via rubber hose. (m) (T+) **
    • Holy Siphon A siphon with holes in it reveals the pressure within. (m) (T+)
  13. Fluid Statics
    • Incompressibility of Water Water filled glass flask to hammer in nails. (m) (T) ***
    • Water Bomb Metal sphere full of water; when sphere is placed on dry ice, water freezes and expands, with explosive results. (m) (T+)
    • Air Spring A piston in a cylinder is hit with a mallet and behaves as if the cylinder were full of springs. (s/m) (T)
    • Archimedes' Principle Spring scale indicates weight of mass in and out of water to demonstrate buoyant forces. (m) (T) *
    • Hydrometer Relative density measurement of liquids in beakers. (s) (T+)
    • Cartesian Diver Buoyancy of diver is changed by amount of water displaced. (s) (T+)
    • Cannon Ball Boat Puzzler Does the level of the ocean rise or fall when a cannon ball is thrown overboard from a boat? (m) (T) **
    • Two-Fluid Buoyancy A polyethelene cylinder floats in water and sinks in vegetable oil. What happens when oil is poured on top of the floating cylinder? (s) (T+)
    • Coke Can Buoyancy Regular Coke sinks in water while Diet Coke floats. (s) (T)
    • Buoyant Force on Finger A finger dipped into a glass of water experiences a buoyant force - made evident by observing the reaction force when the glass is on a pan balance. (s) (T)
    • Buoyant Force Measurement Plastic Coke bottles filled with water, air, and sand are submerged in water. A spring scale is used to determine the buoyant force. (s) (T)
    • Buoyant Soap Bubbles Soap Bubbles float in an aquarium filled with SF6. (s) (T+)
    • Elevator Buoyancy Do ice cubes, floating in a glass of water, float differently in an upward or downward accelerating elevator? (m) (T++)
    • Bean Buoyancy Watch steel and table tennis balls sink and float in this "dried bean fluid". (s/m) (T) **
    • Capillary Action Array of capillary tubes of different bore diameters. (s) (T+) **
    • Giant Bubbles Large rings and powerful bubble mixture for a humid day. (m) (T)
    • Soap Film and String A loop of string floating on a soap film is pulled into a perfect circle by surface tension. (s) (T+)
    • Double Bubble Double your pleasure with this puzzler: small bubble blows up large one. (s) (T+)
    • Holy Boat An open mesh plastic fruit container easily floats on top of water. (m) (T)
    • Minimal Surfaces Soap films on wire frames. (s) (T+)
    • Water Drops Smaller drops are more spherical. Water drops on Teflon are more spherical, but try adding some soap! (s) (T++)
    • Molecular Size Molecular size is determined by means of a Langmuir trough. (m) (T++)
  14. Fluid Dynamics
    • Laminar/Turbulent Flow Depending on conditions, either type of flow can be observed in a glass tube through which water is flowing. (m) (T++)
    • Reversible Fluid Mixing Reversible mixing is accomplished to everyone's amazement. (m) (T+) ****
    • Poiseuille's Law 16-tube water tank to show relation between tube cross-section and flow rate. (l) (T+) **
    • Poiseuille Double Fountain A hose with a smaller opening squirts water higher than an open hose, because of viscosity. (m) (T++)
    • Viscous Fluid Viscosity, Stoke's law, Reynold's number, and terminal velocity is demonstrated at 100 Pascal Sec. (100,000 centipoise). Cooled glycerine can be used to show the temperature dependence. (s) (T+)
    • Parachutes Drag effect of cross-sectional area is demonstrated by two falling disks of paper. (m) (T)
    • Convection Convection in a fluid, by non-uniform heating, is shown. (m) (T+) *
    • Diffusion of Bromine Gas Gas jar containing bromine linked to second containing air. (m) (T++)
    • Diffusion of Colored Water Food coloring placed at bottom of water filled jar. (m) (T+)
    • Resistance to Free Fall Ping Pong balls are dropped in air and SF6 for comparison
    • V2 Drag Accurate determination and analysis of g for falling bodies shows v2 dependency of drag force. (l) (T++)
    • Vortex Large smoke rings are catapulted across lecture hall to blow out candle. (m) (T+)
    • Vortex Tube This clever tube separates hot and cold air out of a jet of room temperature air and serves as a refrigerator. (m) (T++)
    • Turning Off g A cup filled with water has a hole in the bottom. What kind of trajectory does the leaking water experience when the cup is dropped from up high? (l) (T+)
    • Big Squirt / Little Squirt A double fountain puzzler: which fountain squirts higher -- the one with the big opening or the one with the small opening? (m) (T++)
    • Bernoulli's Principle Spinning ball in air stream moves perpendicular to flow in a way dependant on spin direction. (l) (T+) ***
    • Bernoulli Wind Tunnel Tunnel with different cross sections shows that pressure is dependant on air velocity. (l) (T+) *
    • Bernoulli Beach Ball Ball suspended by angled air stream. (m) (T) ***
    • Curve Ball Ping-pong thrower, Styrofoam ball and tennis racquet, or Track Ball set to produce curve balls, floaters, and sinkers. (m) (T)
  15. Strength of Materials
    • Shear Rubber sheet model. (m) (T+)
    • Torsion Rubber tube and wooden slat models are twisted. (s/m) (T)
    • Spiral Fracture Realistic leg-in-ski-boot accident. (m) (T) ***
    • Buckling Wooden slat is compression loaded to buckling point. (m) (T)
    • Foam Rubber Beams The structural strength of these I-beams is easily made evident with small loads. (s) (T+)
    • Hooke's Law and Young's Modulus Both can be determined by stretching a long wire with weights. (l) (T+)
    • Collapsible Cow Scaling of wooden cow, simply and Nature's way. (l) (T+) ***
    • Creep of Lead Lead rod subjected to tensile load. (m) (T+) *
    • Fracture Strength of Chalk Chalk rod subjected to tensile and compressive loads. (m) (T+) *