I’m going to be cross-posting some learning activities from my other enterprise – media.dot.edu – that I work on with Katie Krueger. The focus of the activities is to use entertainment/media based content as a context for learning.
First up, understanding escape velocity using a clip from the Thundermans episode, Report Card.
Topic: Escape Velocity
Episode: The Thundermans, Report Card (Season 1, Episode 4)
Episode Summary: After changing the grades on his report card and being moved into an advanced class, Max competes against Phoebe in the Math Bowl. Meanwhile, Hank, Nora, and Billy try to catch the elusive newspaper thief. (Source: imdb.com)
Video Source: Amazon.com
- Calculate the gravitational potential energy of a system of particles.
- Identify that if a particle moves from an initial point to a final point while experiencing a gravitational force, the work done by that force (and thus the change in gravitational potential energy) is independent of which path is taken.
- Using the gravitational force on a particle near an astronomical body (or some second body that is fixed in place), calculate the work done by the force when the moves.
- Apply the conservation of mechanical energy (including gravitational potential energy) to a particle moving to an astronomical body (or some second body that is fixed in place).
- Explain the energy requirements for a particle to escape from an astronomical body (usually assumed to be a uniform sphere).
- Calculate the escape speed of a particle in leaving an astronomical body.
- Source: Walker, Fundamental of Physics, 10th edition
Standards: Disciplinary Code Ideas (DCIs)
PS2.A Forces and Motion: Newton’s Second Law accurately predicts changes in the motion of macroscopic objects.
PS2.B Types of Interactions: Newton’s Law of Universal Gravitation (and Coulomb’s Law) provide the mathematical models to describe and predict the effects of gravitational (and electrostatic forces) between distant objects.
Forces at a distance are explained by fields (gravitational, electric, magnetic) permeating space that can transfer energy through space. Magnetics or electric currents cause magnetic fields; electric charges or changing magnetic fields cause electric fields (HS-PS2-5)
PS3.A Definitions of Energy: Energy is a quantitative property of a system that depends on the motion and interaction of matter and radiation within the system. That there is a single quantity called energy is due to the fact that a system’s total energy is conserved, even as, within a system, energy is continually transferred from one object to another and between its various possible forms. (HS-PS3-2)
PS3.B Conservation of Energy and Energy Transfer: Conservation of Energy means that the total change of energy in any system is always equal to the total energy transferred into or out of the system.
Energy cannot be created or destroyed, but it can be transported from one place to another and transferred between systems. (HS-PS3-4)
Mathematical expressions, which quantify how the stored energy in a system depends on its configuration and how kinetic energy depends on mass and speed, allow the concept of conservation of energy to be used to predict and describe system behavior.
The availability of energy limits what can occur in any system.
(Source: The NSTA Quick-Reference Guide to the NGSS, High School, NSTA Press, 2015)
In the episode, Evan asks “This thing must need an incredible amount of thrust to break through the inner atmosphere.” Max responds, “Oh, it’s a standard 30 kg rocket and it requires 1100 Nt (of thrust) to achieve escape velocity.”
The question: Is Max correct?
Explore the Concepts
Understanding Conservation of Energy
Understanding Gravitational Field Strength
Understanding Gravitational Potential Energy
Understanding Rocket Thrust
Calculating Escape Velocity
Space Agency by Nooleus (In App Purchases Required)
The goal of the evaluation is to determine if Max is correct. Does it take 1100Nt of thrust for a 30 kg rocket to achieve escape velocity.
Using the concept of conservation of energy and gravitational potential energy (where ), derive the equation for the escape velocity of an object.
Using conservation of energy, gravitational potential energy and Newton’s Laws of Motion, calculate the escape velocity of the rocket. Make sure you list all assumptions.
Screen capture the video and import the video into Vernier Video Analysis. Use video analysis to determine the acceleration of the rocket when it leaves the stand. This should assist you in calculting the force required to launch the rocket into the stratosphere.