Mechanics

Distribute velocity tubes, meter sticks, and stopwatches to the class.

Have them investigate the relationship between distance, time, and velocity.

Constant velocity tubes

Meter sticks

Stopwatches

Guinea and Feather tube

Vacuum pump

Watch Video

BBC Bowling Ball & Feather

Bucket

Styrofoam cups

Water

g-Ball

Cushion

PASCO Shoot the Target setup

Same equipment as PHYS 111 experiment P04

Setup

Aimed Below

Aimed Above

Aimed At

PJ-03

(see also:
N1-08)

Show the class what you will do and how the ball shooter works.

Ask class to predict where the ball will hit (in front, next to, behind the cart).

Cock the ball shooter and give the cart a push.

Set this up before class to make sure the ball shooter is aimed properly and the ball lands in the shooter.

PASCO cart with vertical ball shooter

Trigger

Track (with bumper on the far end) Bubble level

Glass or beaker

Cardboard sheet

Coin

Watch Video

Slow

Fast

Place ball on card on post.
Pull back flicker.

Let go.

Start nail into one piece of wood.
Place padding on head, two pieces of wood on top of padding (hold lumber with your hands to make sure it stays in place).
Get student volunteer to pound the nail into the wood.
Warnings:

1) Try this with a friend first to make sure the padding is thick enough and the lumber has enough inertia.

2) Do not choose the biggest guy in the class to do this.

3) Make sure they miss your fingers (and theirs).

Hammer (standard)

Two pieces lumber - 4.5"x4.5"x12" (or equivalent)

Rubber padding

Large nail (10 or 12 penny)

Put TP on a horizontal metal rod so they are free to spin.

Grab a square of TP and give it a sharp jerk.

The piece of TP from the full roll will be ripped from the roll. The empty roll will spin and the rest of the TP will land on the floor.

Full roll of TP

Almost empty roll of TP

Walk at constant velocity.

Ask class to predict where the weight will hit (in front, next to, behind you).
Drop weight.

Ball

Bucket

N1-08

(see also:
PJ-03)

Show the class what you will do and how the ball shooter works.

Ask class to predict where the ball will hit (in front, next to, behind the cart).

Cock the ball shooter and give the cart a push.

Set this up before class to make sure the ball shooter is aimed properly and the ball lands in the shooter.

PASCO cart with vertical ball shooter

Trigger

Track (with bumper on the far end) Bubble level

Have a volunteer stand on the scale.

If the elevator accelerates upwards they gain weight.

If the elevator accelerates down they lose weight.

Instant diet!

Bathroom Scale

Elevator

Set up plate, glass, for and spoon on top of sheet. (Do so a few inches from the edge of a table.)

Pull the sheet hard to remove the sheet but leave the place setting.

(Practice! Don't pull back on the sheet. Pull down towards the ground. Pull very quickly.)

Heavy plate

Heavy glass

Spoon

Fork

Knife

Silk sheet

Level track and place cart on track. Attach string to cart, over pulley, to mass hanger.

Place mass on hanger.
Release cart - It will accelerate.
Increase the hanging mass - a will increase.
Increase the cart mass - a will decrease.

Dynamics track

Pasco cart

Pulley

String

Hanging masses

15 foot rope

2 kg masses

Two 0-20 N spring scales

0.5 kg mass

Two strings

15' of rope

Two volunteers (large and small)

Moving dolly or wheeled chair

Two lab stands, each with a pulley.

Two mass hangers, each with equal mass (1 kg)

Large circular spring scale

String

Anchor the lab stands so they do not topple inwards.

Dynamics cart

Track

Block with 3 slots, at 0, 45 and 90 degrees.

Solid "sail" that is about 8" square that fits neatly into the slots.

Hair dryer

N3-07

Coming Soon

Reaction cart

Fire extinguisher

Crash helmet for dramatic effect

Sit in one chair:

1) Volunteer pushes you, you go back.

2) You push volunteer, you go back.

Have volunteer sit in other chair:

1) Both push, both go back.

2) You push, both go back.

3) Volunteer pushes, both go back.

Two rolling chairs (must roll well)

Hard floor

One Volunteer

Fill the bottle ~1/3 with water.

Attach launch pad to bottle and stick in ground.

Attach hose to rocket and pump.

2 liter bottle

Rocket launch pad

Hose

Water

Bike pump or air compressor

Attach ballon to race car.

Blow up balloon.

Sit it on table and let go.

3rd law race car

Balloon

Attach fan to collision cart.

Turn on fan and it will push cart along.

Angle fan side to side to investigate force as a vector.

Pasco collision cart

Pasco dynamics track

Fan cart attachment

MO-01

Impulse

Egg Catch

Hold sheet with volunteer.

Hold one end of sheet high and let the other end drape down and back up so it looks like a J in cross section. Do not hold the sheet tight.
Have the other volunteer throw the egg (hard) at the sheet.
Be prepared to clean up after misses.

3 eggs (raw)

Sheet

2 volunteers

Paper towels

MO-02

Impulse

Happy/Unhappy Balls 1

One bounces.
One doesn't.

Happy and unhappy balls

MO-03

Momentum Transfer

Happy/Unhappy Balls 2

Set up the track and block carefully so that when you roll the happy ball down the track it knocks over the block but the unhappy one won't.
Query the class which will knock over the block.
Then do it.

Happy and unhappy balls

Track with lab stand

Wooden block to knock over

MO-04

(see also:
Nuclear-03)

Momentum Transfer

Double Ball Drop

Drop tennis ball.
Drop basketball.
Drop balls together with tennis ball on top.

Basketball

Tennis ball

Watch Video

MO-05

Conservation of Momentum

Air Track Collisions

Various collisions:
A) Elastic (with bumpers)
Same mass, different mass, both moving, one moving
B) Inelastic (need to make this with screws and magnets)
PRACTICE FIRST.

Air track

Blower

Large cart

Small cart

Watch Video - Inelastic

Watch Video - Elastic

MO-06

Energy Transfer in Collisions

Bouncing Dart

Mallet has two different types of rubber on the ends.

Use one end to model inelastic collisions and the other to model elastic collisions.

Bouncing dart mallet

Pasco collision cart

MO-07

Momentum Transfer

Newton's Cradle

Pull one ball back and release.

Pull two balls back and release.

Newton's cradle

EC-01

Conservation of Energy

Bowling Ball Pendulum

Sit in chair immediately in front of boxes (head against boxes).

Pull bowling ball to head, give it a small push, get out of the way!
Redo without pushing the pendulum to show that your head is safe.

Bowling ball pendulum attached to eye in ceiling

Backdrop (eg: table piled with empty boxes)

EC-02

Conservation of Energy

Billiard Ball Race

Use book to prop up the starting end of the track.
Ask class: Which will win the race?
Put billiard balls at start line.

Let go.

Aluminum billiard ball tracks

Two billiard balls

Book

Piezo Transducer

Voltmeter

Oscilloscope

RO-01

Rotation

Bike Wheel

Use to demonstrate rotational position, v,a.
Show that a quarter on the rim will slide off if v is large enough.

Bicycle wheel with handle at hub

RO-02

Rotation

AC Lights

Plug in lights.

Darken room.

Swing in a circle.
Shows that x = r&omega so the larger the radius, the larger the arc covered.

AC lights on a long cord

RO-03

Rotational Stability

Rotational Stability

Roll double cup down track.

Show that the mouth-to-mouth cups roll stably.

Parallel tracks (eg: two meter sticks with a 4" separation)

Double cones:
A)Two paper cups attached mouth to mouth
B) Two paper cups attached base to base

RO-04

Rotational Inertia

Rolling Race 1

Which will win? The weights inside or the weights outside?

Large blue triangular wooden rolling tracks

2 blue rolling disks

RO-05

Rotational Inertia

Balancing Sticks

Easier to balance with mass at the top or the bottom?

Long metal rod

Mass which can be tightened in placeon rod

RO-06

Rotational Inertia

Twisting Sticks

Twist back and forth.
What's the difference?

Pair of sticks which are the same size and same mass

One has weights near center

One has weigths near the ends

RO-07

Rotational Inertia

Racing Pendula

Which pendulum will be faster?

Two pendula

Two lab stands with horizontal bar Moveable weights that attach to pendula

RO-08

Rotational Inertia

Baseball Bat Sweet Spot

Strike bat with mallet (or baseball).
Bell will ring except when struck at the sweet spot.

Baseball bat hanging from its thick end
small bell attached to handle end
Rubber mallet to hit bat

RO-09

Rotational Inertia

Rolling Race 2

Set up two tracks at the same angle.

Roll the objects down the tracks.

Which will win?

Metal hoop and wooden disk of same mass

2 Pasco dynamics tracks

2 lab stands

2 rod pivot clamps

RO-10

Precession and Nutation

3-Axis Gyroscope

Show precession and nutation using a 3-axis gyroscope.

Pasco 3-axis gyroscope

String

RO-11

Inertia of Rest

Falling Chimney

Place the golf ball on the T.

Hold at an angle.

Drop.

(Practice! Sometimes difficult to get the right height or not drop to the side. Working on fixing this unreliability.)

Falling chminey apparatus

Golf ball

Open both discs to show the placement of the steel ball bearings.

Place disks on inclined plane and let go.

Which one makes it to the bottom first?

Variable Inertia Set

Dynamics track

Lab stand

Support rod

Rod pivot clamp.

Observe the angular acceleration of the apparatus, and investigate the effects of changes in torque and inertia. Simply move the rope to a pulley of different radius to change the torque, or move the mass on the arm to change the moment of inertia.

Rotational Inertia Demonstrator

String

Hanging masses

CF-01

Centripetal Force

Loop-the-Loop

When the ball is released from high enough up it will loop the loop.

At lower speeds it will fall off.

Loop-the-loop track

Plastic ball

CF-02

Centripetal Force

Revolving Bucket

Swing bucket in big circle.
Water stays in it

Bucket of water

CF-03

Centripetal Force

Cup on Rotating Tray

Place cup on tray.
Swing in big circle.
PRACTICE!

Tray suspended by string

Cup of water. (Not glass!)

CF-04

Centripetal Force

Coin on Bike Wheel

Place coin on wheel near rim.
Spin wheel.
Coin falls off .

Coin

Bike wheel

CF-05

Centripetal Force

Golf Ball Centrifuge

Place the two jars with the two golf balls on the ends of the beam.

Spin the beam.

Ask the students to explain why the golf ball in jar moves inward and the other moves outward.

Spinning 2x4

2 Plastic Jars

Golf Ball

Practice Golf Ball

Water

CF-06

Centripetal Force

Double Ball Centrifuge

Spin the apparatus and the two balls will travel up the tracks on opposite sides.

Double ball spin apparatus

CF-07

Centripetal Force

Centripetal Force Kit

Attach rubber stopper to one end of the string, pass through the pipe, and attach other end to a hanging mass.

Swing over head.

Rotation will cause the stopper to move outwards and the mass to move upwards.

Need different angular frequencies for different stoppers, different masses, and different lengths of string.

Arbor Scientic Centripetal Force Kit

(String, various rubber stoppers, and plastic pipe.)

Various masses for hanging.

CF-08

Centripetal Force

Ball on a String

Swing ball in a loop overhead. When you let go, the ball flies in a straight line.

Tennis ball

String

AM-01

Conservation of Angular Momentum

Rotating Stool 1

Student sits on stool.
Hold weights at arms length.
Spin stool (not too fast).

Student brings weights in and back out.

Rotating stool

Dumbells

AM-02

Conservation of Angular Momentum

Rotating Stool 2

Student sits on stool.
Spin the wheel for them.

Hand wheel to student in vertical plane.
Tilt wheel one way then the other.

Rotating stoo

Weighted bike wheel with handles

AM-03

Conservation of Angular Momentum

Mystery Suitcase

Remove protective slat from the bottom of the suitcase.
Start the motor spinning (it prefers to spin one way rather than the other, might need to give it a push to start it spinning)
Place the suitcase carefully on the motor so it makes the wheel inside spin rapidly.
Put the protective slat back on.
Ask people to pick up the suitcase, walk with it, turn around, and return.

Mystery suitcase

Motor

AM-04

Gyroscopes

Gyro Wheel

Spin wheel.
Suspend from rope.
Watch precession.

Weighted bike wheel with handles and an attached rope

AM-05

Gyroscopes

Gyroscope

Wind string around axis and pull.

Gyroscope

TO-01

Torque

Balanced Meter Stick

A) Equal weights at equal distances balance.
B) Unequal distances don't.
C) Mr = mR will balance.
D) Hanging the weight lower makes no difference.

Wooden meter stick suspended in the middle

Several meter stick hangers

Various weights
String

CM-01

Center of Mass

Thrown CM

Darken room.
Throw upwards.
Light follows a nice parabola

Wood block with light at CM

CM-02

Center of Mass

Irregular shape CM

Suspend CM demo from stand.

Hhang plumb bob from same point. Draw vertical line.
Repeat for two more points.
Lines intersect at CM.

Irregular shape CM demo

Lab stand to suspend it from

String and plumb bob

CM-03

Center of Mass

Fork and GlassBalance

Put forks tines together and parallel
Insert quarter with one edge between two tines of both forks.
Balance other edge of quarter on rim of glass.
PRACTICE!

Glass

2 forks (identical forks work best)

Coin (quarter works best)

CM-04

Center of Mass

Toe Touch

Touch your toes with your heels against the wall.

CM-05

Motion of Center of Mass

Kick CM

Place paper on ground.
Place CM block on paper.
Kick it so it goes forward and spins.
The central marker will go straight as the side markers swirl around it.

CM block with markers in it

Long sheet of white paper

CM-06

Center of Mass

Ernest CM

Attach string between two lab stands.
Place Ernest on the string.

Ernest the balancing bear

2 lab stands

String

CM-07

Center of Mass

L-Shaped CM

Find the CM.
Show that they balance with the long side down .

Two identical L-shaped objects

CM-08

Center of Mass

Boy/Girl CM

Have each one kneel with elbows to knees.

Place a small object at their fingertips. Put hands behind back.

Try to knock over the object with your nose.

Most males can't do it while most girls can.

Two volunteers

CM-09

Center of Percussion

Pencil Break

Place pencil through handle of bat and pegs on base.

Place the block at the center of percussion.

Lift the bat and drop. Pencil doesn't break.

Move the block away from center of percussion and pencil will break.

(Practice! Works best if the block is moved towards handle end of bat.)

Center of percussion holder

Baseball bat with drilled holes

#2 pencils

4x4 block

CM-10

Center of Percussion

Bell Ringing

Suspend the bat with the bell at the end using fishing line from the two eyelets.

Hit the bat with a rubber mallet.

If you hit it at the center of percussion, then the bell will not ring.

Otherwise the bell will ring.

Center of percussion holder

Baseball bat with drilled holes

Fishing line

Bell