1 and A
2 and B
3 and D
4 and C
The correct answer is <span>3)
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In fact, the total energy of the rock when it <span>leaves the thrower's hand is the sum of the gravitational potential energy U and of the initial kinetic energy K:
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<span>As the rock falls down, its height h from the ground decreases, eventually reaching zero just before hitting the ground. This means that U, the potential energy just before hitting the ground, is zero, and the total final energy is just kinetic energy:
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But for the law of conservation of energy, the total final energy must be equal to the tinitial energy, so E is always the same. Therefore, the final kinetic energy must be
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Answer:
The particle model of matter is one of the most useful scientific models because it describes matter in all three states. Understanding how the particles of matter behave is vital if we hope to understand science!
The model also helps us to understand what happens to the particles when matter changes from one state to another.
The following diagram shows different changes of state, as well as which processes are the reverse of each other. Melting and freezing are the reverse processes of each other and so are evaporation (boiling) and condensation.
Explanation:
B, do earthworms prefer bright light or darkness!