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Before the book is thrown, the potential energy has the highest amount, and when the book falls, the energy changes to energy movement, and when the book falls on the ground, the energy changes again to the potential energy.
The correct answer to this question would be trees.
Answer:


Explanation:
m = Mass of each the cars = 
= Initial velocity of first car = 3.46 m/s
= Initial velocity of the other two cars = 1.4 m/s
v = Velocity of combined mass
As the momentum is conserved in the system we have

Speed of the three coupled cars after the collision is
.
As energy in the system is conserved we have

The kinetic energy lost during the collision is
.
Answer:
Two objects that are the same volume will displace the same amount of water even if they have different masses.