## Use PocketLab to model relationship of friction/stress to frequency and size of Earthquake

This cool demonstration was brought to us via Twitter by Earth and Environmental Science Teacher, Ryan Hollister (follow him at @phanertic).

## Planning to jump out of a spacecraft 24 miles above Earth? Don’t forget your PocketLab!

Exactly 65 years after Chuck Yeager broke the sound barrier in a Bell X-1 aircraft,Felix Baumgartner did too, but not in an aircraft. He did it by jumping out of one. In a state of the art pressure suit, Baumgartner jumped out of a capsule dangling from a helium balloon that had reached the stratosphere, 24 miles from the surface of the Earth. Before deploying his parachute, Baumgartner reached a top speed of 833.9 mph.

## Enter for a chance to win a PocketLab and an iPad on Instructables!

Need some PocketLabs for a classroom or for science exploration at home or work? We've given Instructables 17 PocketLabs and an iPad to give away to the best entries in their Explore Science contest.

## A Quantitative PocketLab Study of Momentum, Impulse, and Force in the Collision of Two Carts

You don't need an expensive air track to do a quantitative study of momentum, impulse, and force involved in the collision of two carts. You can get very good results by the use of two PocketLabs, two iPhones, and a pair of carts from the PocketLab Maker Kit.

## Rotational Dynamics of a Falling Meter Stick

There is a well-known problem in rotational dynamics that involves a meter stick. The meter stick is held in a vertical position with one end on the floor. It is then released so that it falls to the floor. The end initially on the floor is not allowed to slip during the fall. Students are asked to derive an equation that predicts the angular velocity of the meter stick just before it hits the floor. The derivation involves many physics concepts including gravitational potential energy, rotational kinetic energy, conservation of energy, moment of inertia, and angular velocity, thus giv

## Magnetic Field on the Axis of a Current Loop

In this lesson students will find that a current-carrying loop can be regarded as a magnetic dipole, as it generates a magnetic field for points on its axis. The figure below shows a diagram and the equation for the magnetic field B. Derivation of this equation requries knowledge of the Biot-Savart Law, calculus and trigonometry. But in this lesson we are interested only in comparing experimental results from PocketLab's magnetometer to the theoretical equation in the figure below. More advanced students can consider derivation of the equation, if they wish.

## A Quantitative Study of Helmholtz Coils

These coils come in pairs with the same number of windings of wire on each of the two coils. In "true Helmholtz" configuration: (1) the coils are wired in series with identical currents in the same direction in each coil, and (2) the coils are placed a distance apart that is equal to the radius of each coil. When in this configuration, they produce a very uniform magnetic field that is directed along their common central axis.

## Investigating the "Spinning Coin" (Euler Disk) Problem

Most everyone has spun a coin on its edge on a table top, and many find the result quite fascinating. The coin gradually begins to fall on its side while spinning, makes a whirring sound with increasing frequency the longer it spins, and then abruptly stops. The Swiss physicist, Leonhard Euler, studied this back in the 1700's. An educational toy, referred to as Euler's disk can now be purchased on-line and in hobby shops specializing in science. Such disks have been carefully engineered to spin for a much longer time than a coin.

## Measure the Angle of an Incline Plane

**Exploration**

An accelerometer is a device that will measure acceleration forces. These forces may be static, like the constant force of gravity pulling us towards the Earth’s surface, or the force may be dynamic, like an object moving or vibrating. This lab will show how to use to accelerometer to measure the static angle of a ramp as it rotates between 0° and 90°.

**Objective**