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What does the efficiency of a machine indicate?

How much work is done by the machine.

The ratio of useful work output to the total energy input.

How much energy is wasted in the machine.

The amount of energy required to operate the machine.

If a machine has an efficiency of 60%, and 100 J of energy is supplied to it, how much useful energy is output?

10 J.

100 J.

40 J.

60 J.

What is the formula for calculating mechanical advantage (MA)?

MA = (Output work / Input work).

MA = (Effort distance / Load distance).

MA = (Output force / Input force).

MA = (Input force / Output force.

Which of the following is a typical use of a pulley in a building site?

To change the direction of force without changing its magnitude.

To lift heavy materials to a higher point.

To amplify the force required to move a load.

To reduce friction in moving parts.

What is the main purpose of using an inclined plane?

To transfer energy.

To reduce the force required to lift an object by spreading the work over a larger distance.

To change the direction of the applied force.

To increase the force required to move an object.