Because the center of mass of the pulley does not move up or down. So, the pulley does have gravitational potential energy, it just isn't relevant.
•Lever
Lever allow us to lift heavy weights without too much effort by multiplying the force we apply through simple mechanical advantage. It requires kinetic energy to function because levers will not be able to move objects unless an outside force moves them.
•Wedge
Wedge remains a constant, which is equation says. Individually, the wedge increases in energy (kinetic) while the particle loses the same energy - its loss in potential energy is more than what it gains in kinetic.
•Inclined plane
Incline plane the mass is still at rest, so the mechanical energy . At the bottom of the incline, the gravitational potential energy, would be all converted to kinetic energy.
•Screw
The screw has mechanical energy that is converted to potential energy stored in the ball.
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Verified answer
•Pulley
Because the center of mass of the pulley does not move up or down. So, the pulley does have gravitational potential energy, it just isn't relevant.
•Lever
Lever allow us to lift heavy weights without too much effort by multiplying the force we apply through simple mechanical advantage. It requires kinetic energy to function because levers will not be able to move objects unless an outside force moves them.
•Wedge
Wedge remains a constant, which is equation says. Individually, the wedge increases in energy (kinetic) while the particle loses the same energy - its loss in potential energy is more than what it gains in kinetic.
•Inclined plane
Incline plane the mass is still at rest, so the mechanical energy . At the bottom of the incline, the gravitational potential energy, would be all converted to kinetic energy.
•Screw
The screw has mechanical energy that is converted to potential energy stored in the ball.