# physics interactives

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You can pull in any direction, and see a complete free body diagram, position, velocity, acceleration, force - time graphs.

Faster version with no graphs

A velocity graph with optional speedometer, accelerometer, and motion diagram for two cars. Adjust top speeds and initial accelerations. Toggle between constant speed mode for each car.

I like to start with this video: World's Greatest Drag Race, then have the essential question be: Why did the GT-R win with one of the slowest top speeds? Afterwards we look at 0-60 times for these cars here.

Along the way, students can discover:

The difference between velocity and acceleration

How to determine position, displacement, velocity, and acceleration from a velocity time graph.

Other questions to explore:

When are the cars at the same speed and how is this demonstrated on the graph?

When are the cars at the same place and how is this demonstrated on the graph?

Demonstration of Relative Velocity

Switch between different observers' reference frames and see motion and position, velocity and acceleration graphs.

Connecting motion diagrams, position time graphs, and a uniformly accelerated motion equation.

Velocity time graph for a car moving forward and back.

The goal here for my students is again to differentiate between velocity and acceleration with the added complexity of positive and negative velocity and acceleration.

In addition, students can explore how to determine position, displacement, velocity, and acceleration from this more complex velocity time graph.

Jay Chow created a fantastic position time graph activity with Turtle Crossing.

With this new one, you can draw the *velocity-time* graph, watch the resulting motion, and see the corresponding position-time graph. In addition, you can see the corresponding velocity-time graph from a drawn position-time graph.

(Still a work in progress. At the moment it is just a proof of concept.)

Acceleration time graph for an "elevator".

Students can adjust the graph directly and see how that affects the motion. In addition, students can change the initial velocity and position and notice how that affects the graph and motion.

By the end, students should be able to explain the effect of the area under the curves on the change in velocity, as opposed to the velocity, displacement, or position.

Visualize 3 uniformly accelerated motion equations on a velocity time graph.

Sometimes I find this to be a better "derivation" of these equations than grinding through the algebra, especially early on in the year when students are just getting used to the math and what a derivation is.

Also, I wrote the equations on the board once in those colors several years ago, students started referring to them that way and they will now forever be those colors. (The v^2=v_0^2+2a∆x is green in case you needed to know).

Desmos Classroom activtiy with the ability check each step of an algebraic derivation from kinematics equations.

Falling with air drag force.

Motion and force vectors. Motion, Force, and Energy vs. time and height graphs.

A challenge that just hints at 2-dimensional motion. Inspired by an Algodoo scene from David Dougherty.

When is 45° not the angle with maximum range?

What happens if hold one initial velocity component fixed, and only change the other one?

Hit a stationary or moving target with a projectile!

Start off with a stationary roadrunner, then one with a constant velocity, then uniformly accelerated.

You can turn off the roadrunner and focus on projectile motion concepts as well: motion diagrams, velocity vectors and displacement vectors.

Explore some inertial and noninertial frames of reference

Adjust angles and monkey weight for a monkey.

Ways to use this:

Students can explore the relationship between the horizontal components, and independently the vertical components.

Students can explore how changing the angle changes the tension force, then try to explain why geometrically that must happen in the symmetrical situation and the asymmetrical situations.

Students can explore which rope always has more tension force in assymetrical situation, starting from one at 90°

Also working on a "game" where students must match the tensions: Monkey Statics Game

A way to visualize the frictional force. Adjust weight, tension force magnitude and direction, and a downward pushing force magnitude.

Students always find static and kinetic friction problems so hard, and rightly so, there are so many different things that can happen, two different graphs we often use that have friction on the y-axis, and it depends on the normal force which they are confused by and isn't even in the same dimension as the friction force.

Hoping to help some of that confusion with this and the following two desmos.

A way to visualize the frictional force. Adjust weight and pushing force magnitude and direction.

Trying to describe what happens when you change how hard you push against the wall is difficult. I like this visual for that situation, because you can see the point on the graph doesn't change, but the graph changes around it.

There's also some interesting dynamics as you change the angle of your push that are fun to explore.

A way to visualize the frictional force. Adjust weight, angle, and add a tension force at any angle.

As the angle changes, the frictional force can change for different reasons, depending on the angle.

Simple visualization of how changes in the normal force alone accelerate something on an elevator. Explains changes in the scale reading.

I like to start with this video: Elevator and Scale (Can't remember where I got it though!)

Using the simulation students can answer why the scale reading must change to not match the weight, as well as make calculations and predictions more easily than from the video (which is also worth doing).

Trying to make a more student friendly version of this. Have student think about position, velocity, 2D motion and Newton's Laws all at once! May try to add rotation and the z-direction eventually.

Try to get the puck to move in a circle. See the radial and tangential components of the force, and how they change the motion. Also, see the instantaneous radius of curvature for the motion.

You are trapped on a spaceship with your fellow students. Only your physics skills can save you now.

Centripetal Force

Orbital velocity

(Inspired by Joe Cossette's activities)

Collision carts with position, velocity, momentum, and force vs. time graphs, momentum diagrams, and energy charts. View motion of each cart and center of mass, and create spring-loaded "explosions".

Bounce, Catch, and Through!

We usually do this demonstration live, but we're all remote this year, so there needed to be some replacement. Most other simulations I've found don't let the objects go through each other, which is an important scenario.

Made by William H Calhoun, based on an idea from Brian Frank, modified by me. See the connections between conservation of momentum, Newton's third law, and impulse-momentum here. See graphs at the same time.

Block is pushed by a spring then comes to a stop on a rough floor. See energy-position graph.

Cart attached to a spring undergoing simple harmonic motion.

Cart on a Spring with damping and driving force terms.

Comparing motion with the same angular velocity and motion with the same tangential velocity. Also gets a good intuition for what a radian and a radian/sec are.

Static equilibrium. Balance forces and torques.

Rotational equivalent of the dynamics cart above.

Spin a cylinder with a string.

Examine rotational kinematics and dynamics.

Rolling cylinders up a hill!

Look at paths of points on the object, velocity vectors, force vectors, and energy.

Based on a desmos by Brian Frank

Compare rolling objects up a hill at the same speed and changing rotational inertia, angle of incline, radius, gravitational strength.

Based on a desmos by Brian Frank

Drop a spinning solid cylinder or a particle on a spinning solid cylinder.

Like marble hitting the cart, but the target can spin, translate, or both! Students can explore when kinetic energy, translational momentum, and angular momentum are conserved.

Conservation of Angular Momentum in a Diver. Qualitative for now.

Adjust sizes and shapes of two wave pulses to see how they interact with each other.

Adjust sizes and shapes of two wave pulses to see how they interact with each other.

Adjust amplitude and width of two wave pulses to see how they interact with each other.

Adjust the waves to practice waves vocabulary. Could also be used to practice calculating and measuring wavelength.

Practice for waves vocabulary. Infinite randomized practice.

Very quick demo I'd give as a warm up. 3 traveling waves:

Two have the same wavelength.

Two have the same frequency.

Two have the same speed.

Explore electromagnetic waves and polarization in 3D.

Well, more of a butter orb. Inverse Square Law a la Eric Rogers: https://archive.org/details/coulombs_law

Not sure if it's useful, but someone asked about it and it was kind of fun to make. (older version Butter Gun drawing from Conceptual Physics)

Inspired by a request from Bree BarnettDreyfuss on Twitter (@BarnettDreyfuss), a more modifyable version of this from Andrew Duffy

Infinite Practice for "drawing" tangent lines

I may have found these through a search, I'll attribute if I can find the author.

Just to visualize what happens when you change a numerator vs. a denominator.

# Regressions

I may have found these through a search, I'll attribute if I can find the author. I'd like to make it a little more student friendly and have the variables all on the screen.

# Resources

Graph Maker (Remixed from Joe Milliano's work, v5)

Friction by Trey Goesh