Machine – Science
The device or instruments, which make our work easier, faster and convenient are called simple machines. Lever, Wheel & axel, Pulley, Inclined plane, Screw and Wedge are simple machines.
Mechanical Advantage: The ratio between load raised and effort applied in a simple machine is called mechanical advantage. It has no unit as it is a simple ratio of two forces. It is affected by friction. M.A.= Load(L) Effort(E)
Machine Velocity ratio: The ratio between distance travelled by the effort and the distance travelled by the load is called velocity ratio. It has no unit because it is a simple ratio of two distances. It is not affected by friction. V.R = E.D/L.D
Efficiency: The percentage ratio of output work to the input work is called efficiency.
In another way, it can be defined as the ratio of output work to the input work. It is expressed in terms of percentage.