APC
Artifact Preservation & Co.
Behind our Transportation Mechanism
KINETIC ENERGY
GRAVITATIONAL POTENTIAL ENERGY
NEWTON'S FIRST LAW
IMPULSE-MOMENTUM
WORK & POWER
An object at rest will stay at rest unless acted upon by an unbalanced force, an object in motion will stay in motion unless acted upon by an unbalanced force.​​
For the mechanism to commence, man power is used to exert an unbalanced force on the Moai. This causes the Moai, which is at rest, to move.​​
Then, when lifting the Moai to the Ahu using a pulley technique, the force applied to lift the Moai through string is unbalanced and greater. Therefore, the force of tension will pull the Moai up and force it to move upward.
Furthermore, when the car is moving from the slope to the Ahu, the Moai is also in motion. If an unbalanced force were to hit the car, because of Newton’s first law and inertia, the Moai would continue in motion because the force was only acted on the car.
NEWTON'S SECOND LAW
A net force ≠0 causes an object to accelerate
When the Moai is first pushed, it moves because the net force is not 0 and the force applied is greater then the force of friction, causing th object to accelerate.
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Later, when the car is still waiting on the slope, with sticks inserted in between its wheels to prevent it from moving, it is at rest and therefore at anet force of 0. Once the stick is removed, the car begins to move because the forces applied to the car are no longer balanced.
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Finally, when the Moai has to be transported by the pulley, and since the Moai has a great inertia, the force exerted on the Moai has to be greater than it’s pre existing horizontal normal force to cause it to move.
NEWTON'S THIRD LAW
Every action has an equal and opposite reaction.
A normal human being could not make the whole transportation mechanism work just by using manpower because it requires a great amount of force. If they were to exert a force to a twenty ton Moai, it wouldn’t move, since the person pushing it would receive an equal and opposite reaction.
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Because of its great mass, the Moai will have a greater inertia and therefore will have a greater resistance to change in motion. Therefore, a big force has to be applied for the Moai to overcome the static friction and start moving.
A force applied over a certain amount of time causes an object to change in velocity.
F • t = m • ∆v
When the Moai is pushed onto the slope the impulse it gets causes a change in momentum. The force exerted to move the Moai over a certain amount of time causes the Moai to change its velocity.
When the Moai is first pushed, the force causes it to change from being at rest to being in motion. When it is being lifted through the pulley mechanism, the force exerted is different and therefore causes a different change in its velocity.
Work is a net force that causes displacement.
W = Fnet × S
When the Moai is first pushed by manpower it slides down the slope. The force applied on the Moai makes it do work because it causes it to move. When the Moai is being pulled by the pulley both horizontally and vertically, work is being done because the Moai is physically moving upwards and being lifted in vertical position.
Work over time.
P = W/t
Because the work being done to the Moai occurs over a certain amount of time, power is also being applied.
If we wanted to transport the Moai from the quarry to the ahu quickly, we would need to exert greater power. Therefore, its preferrable to move it slowly because less power will be required to transport the Moai.
The energy an object gains by being lifted.
GPE: m × g × h
When the Moai is at the top of the hill, its gravitational potential energy is 215977 joules.
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The total kinetic energyof the Moai since it is first pushed off the cliff and onto the longs is of 215977 joules. This energy was initially gravitational potential energy but was later converted to kinetic when it started moving.
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The energy of an object in motion.
KE = 1/2 m v^2