It’s basically that’s any system that’s closed to all transfers of matter and energy the mass of the system has to remain constant over time because they can’t change meaning you can’t add or remove from it
Answer:
c) kg
Explanation:
Kilograms stands alone. It has to be hooked up to another unit for it to be a derived unit.
I am joyous to assist you anytime.
Explanation:
Because when two equal forces are applied from opposite directions, they "eliminate" each other.
The train would go right if a 3N force was only applied in the right direction, and it would go left if the same force was only applied to the left.
If a 3N force was applied to the right and a 2N force to the left, it would equal a 1N force to the right (3-2=1).
But there it's 3-3=0, so in practice the force is 0N. Therefore the train won't move.
Answer:
The book sitting on the desk
Explanation:
The gravitational potential energy of an object is the energy possessed by the object due to its position relative to the ground.
It is calculated as:

where
m is the mass of the object
g is the acceleration due to gravity
h is the height of the object with respect to the ground
From the formula, we see that the GPE of an object is directly proportional to the heigth h: so, the higher the location of the object, the larger the GPE.
In this problem, we are comparing a book sitting on a desk and the same book sitting on the floor. In the two situations, the mass of the book is the same; however, in the first case, the value of the height is h, while in the second case, the value of h is lower (because the book is located at a lower height, being on the floor).
Therefore, we can conclude that the first book must have a larger GPE, since it has a larger value of h.