Actually, work has alot more definitions than the one being described

in most of the tethered swimmer analysis. Yes, in a LINEAR mechanical

system work equals the integral of force acting through a distance, which

for a CONSTANT force is

Work = force x displacement.

In a ROTATIONAL mechanical system, the work is found by the integral of

torque acting through an angular displacement. Again for constant torque

Work = Torque x angular displacement.

There are other types of systems, so of course there are other types of

work, mainly electrical work and fluid work.

The tethered swimmer can be analyzed in a variety of ways depending on what

the real question is in regard to work. Net translational work done on the

mass? Rotational work produced by the arms? Biomechanical work produced by

the muscles? Total work done on the water? As others have said, the first

job in analyzing a problem of this sort is to identify the system of

interest.

The net translational work is easy to identify (zero displacement, zero

work), but all of the other calculations are extremely complex since the

torques, forces, local water pressure, etc are changing with time.

- Heather Abushanab

BU NeuroMuscular Research Center

in most of the tethered swimmer analysis. Yes, in a LINEAR mechanical

system work equals the integral of force acting through a distance, which

for a CONSTANT force is

Work = force x displacement.

In a ROTATIONAL mechanical system, the work is found by the integral of

torque acting through an angular displacement. Again for constant torque

Work = Torque x angular displacement.

There are other types of systems, so of course there are other types of

work, mainly electrical work and fluid work.

The tethered swimmer can be analyzed in a variety of ways depending on what

the real question is in regard to work. Net translational work done on the

mass? Rotational work produced by the arms? Biomechanical work produced by

the muscles? Total work done on the water? As others have said, the first

job in analyzing a problem of this sort is to identify the system of

interest.

The net translational work is easy to identify (zero displacement, zero

work), but all of the other calculations are extremely complex since the

torques, forces, local water pressure, etc are changing with time.

- Heather Abushanab

BU NeuroMuscular Research Center