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In a machine with a mechanical advantage (MA) of 4 and a velocity ratio (VR) of 5, what is the efficiency?

50%.

100%.

60%.

80%.

Which of the following machines is a type of lever?

Wheelbarrow.

Inclined plane.

Pulley.

Simple ramp.

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 reduce friction in moving parts.

To lift heavy materials to a higher point.

To amplify the force required to move a load.

What is a machine?

A device that reduces the amount of force required to do work.

A device that changes the direction of the applied force.

A device that helps in doing work by transmitting or transforming energy.

A device that does not require force to work.

What is the purpose of a simple machine like a lever or pulley?

To make work easier by increasing force or speed.

To reduce the displacement required.

To increase the input energy.

To change the direction of the applied force.