4.1.1.P6

A paramecium swimming through a fluid is moving at approximately a constant velocity as a result of wiggling its cilia. What can you say about the various forces that are being exerted while it is doing this? Complete each of the sentences below by filling in the blank with the one of the following symbols that is closest to being true: >> (significantly greater than), > (a little greater than), = (equal to), < (a little less than), << (significantly less than).

1. Since the paramecium is moving through the fluid at a constant velocity, the magnitude of the net force on it must be ____ zero.
2. The magnitude of the force that the paramecium’s cilia exert on the water must be _____ the magnitude of the force that the water exerts back on the cilia.
3. The magnitude of the force that the paramecium’s cilia are exerting on the water will be _____ the magnitude of the viscous force of the water acting on the paramecium.

    

Joe Redish 1/15/13