Education Standards

Demonstration Videos

Demonstration Videos

Overview

Video demonstration experiments show the laws and concepts in action.

Nose Basher

The Nose Basher is simply a pendulum with a massive bob. The presenter raises the bob up to their nose, keeping the string taut, displacing the pendulum away from its equilibrium point. Once released from rest, it makes one oscillation and  returns to the presenter, but the presenter is safe due to the conservation of energy, ensuring that the pendulum will not swing beyond the initial point of release. However, if the bob is pushed with the release, then this additional energy will result in an increase in the pendulum’s final height beyond the initial height. That is why it is important to release it from rest.

Nose Basher

 

Stopped Pendulum

This demonstration is an example of the conservation of energy. We have a pendulum that is raised to some height, indicated by the horizontal rod, and then released. The pendulum swings towards and past its equilibrium point and swings back to its initial height, suggesting that its energy was indeed conserved. Next, we add a rod that will be in the path of the pendulum’s swing. We raise the bob to the same height as before and release it.  The rod interrupts the swing of the pendulum, essentially becoming a new pivot point and decreasing the length of the pendulum. Due to the shortening of the string length, the period of the pendulum decreases. But, this barely changes the total energy of the system, and the pendulum once again reaches the same initial height. This indicates that the energy was conserved.

Stopped Pendulum

 

High Road, Low Road

The two identical balls have the same starting and ending height, so they both end with the same kinetic energy and velocity. Although the ball on the high road has to travel a shorter overall distance than the ball on the low road, the “low” ball gets accelerated to higher velocities due to gravity at the dip, quickly covering the extra distance, and decelerating only at the end to the same velocity as the “high” ball. This allows the “low” ball to reach the finish first.

High Road, Low Road