These Next-Time Questions are for you!

Next-Time Questions are favorite insightful questions I have asked my students over my teaching career. I have embellished them with cartoons to catch interest. Their intention is to elicit student thinking. My use of them was posting several in a glass case outside my lecture hall—without answers. The wait-time for answers was one week. I could have called them Next-Week Questions, which would have been more appropriate.

Most of these have been published over the years as Figuring Physics in The Physics Teacher magazine. They have also been in ancillaries to my Conceptual Physics textbooks, and physical science textbooks as well. My hope is that teachers will pose the questions, and withhold answers to “next time,” which could be as early as the next class meeting. Their educational value is the long wait time!

Although these are copyrighted, teachers are free to download any or all of them for sharing with their students. But please, DO NOT show the answers to these in the same class period where the question is posed!!! Do not use these as quickie quizzes with short wait times in your lecture. Taking this easy and careless route misses your opportunity for increased student learning to occur. In my experience students have benefited by the discussions, and sometimes arguments, about answers to many of these questions. When they’d ask for early “official” answers, I’d tell them to confer with friends. When friends weren’t helpful, I’d suggest they seek new friends! It is in such discussions that learning takes place.

You may wish to project these Next-Time Questions rather than post them. One or two projected at the end of a class session is fine. The answer is given “next time” the class meets—or at some interval where wait time is at least a day.

These Next-Time Questions are the outcome of my long and wonderful teaching career. They’re yours at the click of a mouse. Please use them as I suggest.

~ Paul Hewitt

Science - Linear Motion

Heat

• Scientific Claim

• Strength or Weakness?

• Sun Diameter

• Downstream Flow

• Channel Tracks

• Average Speed

• Bikes and Bee

• Air Speed

• Sparkler

• Fire Walk

• Radioactive Granite

• Radiation Emitters

• Energy Glow

• Wave Emitters

• Coffee Cream

• Clear or Cloudy

• Radiator

• Cookware

• Space Gear

• Thermostat Setting

Newton's 1st & 2nd Laws

Thermodynamics & Thermal Expansion

• Scaffold

• Pellet Path

• Ball Path

• Elephant and Feather Drop

• Ball Drop

• Falling Nellie

• Ball Toss

• Skidding Distance

• More Skidding Distance

• Accelerating Block

• Dart Gun

• Half-Way Up

• Pisa Drop

• Tippity Top

• Book Friction

• Helium Temperature

• Twice as Hot

• Lamp Efficiency

• Nellie's Fuel

• Metal Ring

• Gap

• Open Ice Pockets

Newton's 3rd Law

Change of Phase

• Scale Reading

• Reaction Force

• Apple On Table

• Strong Man

• Tug of War

• Tugging Distance

• Rubber Band Stretch

• Escaping Molecules

• Double Boiler

• Wood/Metal Ice Melt

• Steam Amount

• Evaporative Cooling

• Air Cabin Temperatures

Vectors

Vibrations, Waves & Sound

• Ground Speed

• Motorboat Race

• Nellie on Clothesline

• Book Friction

• Sailboat Speed

• Wind Impact

• Standing Wave

• Shock Wave

• Speed of Sound

• Pitch

• Violin

Momentum

Light Properties

• Crunch

• Massive Wall

• Jocko Catch

• Recoiling Gun

• Frog Drop

• Ice Sail Craft

• Radio Wave Speed

• Speed of Light

• Emitters

• Colored Lamps

• Interference Colors

• Crossed Polaroids

• Polaroid Glasses

Energy

Reflection of Light

• Cannon Recoil

• Long Cannon

• Roller Coaster

• CO2 Emission

• Bumpy Tracks

• Ball Off Cliff

• Fermat Reflection

• Minimum-Size Mirror

• Mirror Image Distance

• Pocket Mirror

• Bridge Reflection

• Reflection on Water

Rotational Motion

Refraction of Light

• Rollers on Track

• Trucks on Hill

• Shaking Berries

• Fruit-Juice Race

• Bubbles

• Up the Incline

• Spheres

• Weighted Stick Drop

• Torque Pull

• Balanced Broom

• Maximum Overhang

• Ball in Cone

• Normal Forces

• Tether Ball

• Rotating Cans

• Refraction in Water

• Spear Fishing

• Laser Direction

• Under Water Vision

• Equinoxes

• Red Lunar Eclipse

• Lens Filter

• Rainbow Photo

Gravity

Electrostatics

• Gravity Lock

• Earth Rise

• Apple Drop

• Shuttle

• Giant Plane

• Solar Black Hole

• Moon on a Cable

• Lunar Tides

• Body Tides

• Moon Orbit

• Electrical Force

• Water Stream

• A No-No Touch

• Touch and Jolt

• Gravity and Electrons

Projectiles & Satellite Motion

Electric Current

• Pitching Speed

• Golf Ball Paths

• Monkey Shoot

• Bulls Eye

• Orbital Speed

• Escaping the Sun

• Rocket Fire

• Chain Drop

• Van De Graaff Lighting

• Bulb Reversal

• Resistance

• Battery Demo

• Bulb Brightness

• Brighter Glow

• Yum Circuits

• Power Lines

Atoms & Solids

Magnetism

• Germanium Capsules

• More Atoms

• Proton Change

• Hole in the Branch

• Wet Sand

• Growing Infant

• Boxes of Bearings

• Magnetic Force

• Loop

• Iron Bars

• Galvanometer Reading

• Overheating Motor

Liquids

Nuclear Physics

• Water Level

• Equal Areas

• Loaded Fire Truck

• Water Touch

• Teabag Tension

• Styrofoam Load

• Submarine

• Iceberg

• Density of Block

• Lunar Ice Cube

• Sandy Pool

• Scrap Iron Float

• Balsa Wood and Rock

• Ball Challenge

• Decay Rate

• Hydrogen VS Helium

• Neutron Activity

• Decay Energy

• Fission-Fusion Curve

• Fission Energy

• Fusion Energy

• Fusion Reactions

Gases

Special & General Relativity

• Weight of Air

• Pinched Bottle

• Balanced Balls

• Air Pressure

• Air-Filled Floating Balloon

• Balanced Balloons

• Wood and Iron

• Deep Glass

• Spinning Candle

• Candle in Shuttle

• Burning Candles

• Ozone Thickness

• Bernoulli Bubbles

• Bernoulli Puff

• Relativistic Aging

• Length Contraction

• Relativity Test

• Dark Night Sky

• Ball and Light Drop

Exponential Growth

• Beanstalk

• Paper Fold