- Mechanical Advantage (MA) is calculated as the ratio of Output Force to Input Force: MA = F_out / F_in.
- Mechanical Advantage can also be calculated as the ratio of Distance of Effort to Distance of Resistance: MA = D_E / D_R.
- If MA = 1, the output force equals the input force.
- If MA > 1, the machine multiplies the input force, resulting in an output force greater than the input force.
- If MA < 1, the machine reduces the input force, resulting in an output force less than the input force.
- In the example with a block and tackle, using an input force of 10 N to lift a 50 N weight gives an MA of 5 (50 N / 10 N).
- In the same example, pulling the rope 10 meters to raise the weight 2 meters also gives an MA of 5 (10 m / 2 m).
- Mechanical Advantage has no units because the units cancel out in both calculation methods.
- The six simple machines are: Screw, Wheel and Axle, Wedge, Lever, Ramp or Incline Plane, and Pulley.
- Gears are considered by some to be a seventh simple machine but are technically levers on wheels.
- Output Force is the force exerted by the machine on the load.
- Input Force is the force applied to the machine by the user.
- Distance of Effort is the distance over which the input force is applied.
- Distance of Resistance is the distance the load moves.
Parent Tip: Review the logic above to help your child master the concept of simple machines mechanical advantage worksheet.
