Physics 243
Assignment #1

Date Due: January 26, 2018

Please solve the following problems. Each is worth 6 marks

Unit N 10: N10R.1

Unit Q: Q1M.2, Q1R.3

General Questions

  1. I want you to test the applet "spring" which can be found at spring applet

In particular I want you to assess:

  • whether or not it provides a correct period (or frequency) for any given set of mass and spring constants
  • whether or not it provides accurate graphical output of such things as x-t and v-t.

Choose 5 combinations of mass and spring constant to do this and compare what the applet states with what you calculated by hand.

  1. Use EXCEL to investigate the equation for a travelling wave. Specifically, prepare a graph in which you show the wave y = 2.5sin(4x-5t) between x = -4m and x = +4 m and for times t = 0, 0.25, 0.50, 0.75 and 1.0 s. Explain how your graph shows that this wave really is moving, also identifying the direction in which it is moving and how fast the wave is moving.

  2. A spring of mass 1g and k = 10 N/m is attached to a 400g mass which is then pulled 10 cm away from equilibrium. If the mass is released at time t = 0s determine its position, velocity and acceleration at time t = 2.1 s. You may ignore friction and any other possible damping effects on the spring-mass system. Use Excel to prepare a graph showing the kinetic and potential energy in the system over the 2.1 s in question.
  1. A clever entrepreneur has created an "elevator by tunneling through the earth! To send a package to the other side of the earth you simply drop it down the hole! How long does it take for the package to emerge from the hole? Show that:
    • this is an example of SHM
    • the period is comparable (but not the same as) the orbital period of a satellite travelling around the earth in a circular orbit of radius R