Teaching Physics with the Physics Suite
Edward F. Redish
In the figures at the right are shown two systems: a cart moving back and forth on a spring and a swinging pendulum. The graph below can be used to show the back and forth displacement of both systems as a function of time as long as the pendulum is kept at a small angle.
A. Three instants of time are marked on the graph: A, B, and C. Complete the table below by indicating the direction of the quantity for the two cases using one of the following symbols: L (Left), R (Right), U (Up), D (Down), 0 (Zero), or S (Some other direction – draw an arrow to indicate which).
|Velocity at A|
|Velocity at C|
|Acceleration at B|
|Net force on m at B|
B. If you knew m, could you calculate the length of the pendulum, L? If yes, explain how. If no, explain why not.
Page last modified Janaury 27, 2011: O50