To protect the constitutional right to confront ones accused
The trains take <u>57.4 s</u> to pass each other.
Two trains A and B move towards each other. Let A move along the positive x axis and B along the negative x axis.
therefore,

The relative velocity of the train A with respect to B is given by,

If the train B is assumed to be at rest, the train A would appear to move towards it with a speed of 170 km/h.
The trains are a distance d = 2.71 km apart.
Since speed is the distance traveled per unit time, the time taken by the trains to cross each other is given by,

Substitute 2.71 km for d and 170 km/h for 

Express the time in seconds.

Thus, the trains cross each other in <u>57.4 s</u>.
The book is lifted upward, but gravity points down, so the work done by gravity must be negative (so you can eliminate options 1 and 3).
The force exerted on the book by gravity has magnitude
<em>F</em> = <em>mg</em> = (10 N) (9.80 m/s^2) = 9.8 N ≈ 10 N
You raise the book 1.0 m in the opposite direction, so the work done is
<em>W</em> = (10 N) (-1.0 m) = -10 J
By definition, the law of conservation of energy states that:
Ei = Ef
Where,
Ei: initial energy
Ef: final energy
Therefore, no matter the type of energy, always the final energy is equal to the final energy.
Energy can be transformed into another type of energy. For example, the potential energy can be transformed into kinetic energy.
Also, energy is not created, nor destroyed.
Answer:
The following is not true about the Law of Conservation of Energy:
A. It states that the total energy in the universe keeps increasing.
Acceleration will be 9.81 if it goes downwards. If it accelerates upwards it will be -9.81m/s^2