Marble-ous Ellipses – Speed and time of orbiting bodies
Brief description:
In this activity, students will use an elliptical board to obtain speed and distance
measurements for an object in an elliptical orbit.
The results are then plotted on a graph of speed against time in order to understand how gravity effects (or changes) the speed of a planet or a satellite in an elliptical orbit.
It is recommended that students have background knowledge in the concepts of kinetic energy and gravitational potential energy, as well as the concept of velocity vector before beginning this activity.
Subject:
Science, Physics, Mathematics
Learning Objectives:
Students should be able to construct a graph of speed against time and link this to ideas of acceleration and distance to understand the
principles of orbital mechanics.
Students should understand how the strength of gravity varies with distance from a planet or star.
Students should relate this to how a planet
or satellite accelerates and decelerates in an elliptical orbit.
Activity 1: Measuring speed and distance on an elliptical board
In this activity, students will use an elliptical board to obtain speed and distance measurements for an object in an elliptical orbit.
The results are then plotted on a graph of speed against time in order to understand how gravity affects (or changes) the speed of a satellite in an elliptical orbit.
Students are then asked a series of questions on the graphs produced during the activity, and a discussion on comet observations and explanations finishes the actvitity.
Equipment
Ellipse board – made in advance, for instructions see Appendix: Elliptical board template instructions
About 75 small marbles (a few small ones are useful to fill in the sharp end of the wedge)
2 x metre rulers or rods
50 cm of string
Non-permanent marker
Did you know?
For thousands of years, philosophers and astronomers argued about the nature of the structure of the Solar System and beyond.
Two conflicting models for our Solar System emerged: geocentric (or Earthcentred) and heliocentric (or Sun-centred). Around 200 BC, the ancient Greek astronomer Aristotle was a supporter of the geocentric model and proposed that the planets (and the Sun) moved at uniform speeds along circular paths around the Earth, which was at the centre of the Universe.
We know now that this model does not fit with observations of the universe, and instead the heliocentric model has been accepted.
Illustration of the geometric model - the belief that the Earth lies at the centre of the universe
Brief description: In this activity, the principle of moments is applied to rotating systems to demonstrate the concept of a barycentre, or centre of mass,
Brief description: In this set of activities students will learn how scientists study exoplanets with telescopes, using the transit method. Students will characterise exoplanets using
Brief description: In this activity, teachers and students simulate a comet nucleus in the classroom. Comets are considered to be time capsules containing information about