T. A. Weston's differential type of this device relies on two unequal radii
T. A. Weston's differential type of this device relies on two unequal radii, and little g can be measured by the motion of two masses about one of these in an Atwood machine. The movable type of this device has twice the  mechanical advantage of the fixed type, and a system of multiple ones is known as a block and tackle. Precise  calculations need to account for the moment of inertia and friction of their sheaves. Often used to transmit rotational motion between shafts, name this simple machine that makes lifting easier by accommodating a belt, chain, or rope through its outer groove.
T. A. Weston's differential type of this device relies on two unequal radii, and little g can be measured by the motion of two masses about one of these in an Atwood machine.