True, an object at rest stays and rest and an object in motion stays in motion
Answer:
The friction force is 250 N
Explanation:
The desk is moving at constant velocity. This means that its acceleration is zero: a = 0. Newton's second law states that the resultant of the forces acting on the desk is equal to the product between mass (m) and acceleration (a):

In this case, we know that the acceleration is zero: a = 0, so also the resultant of the forces must be zero:
(1)
We are only interested in the forces acting along the horizontal direction, since it is the direction of motion. There are two forces acting in this direction:
- the pull, forward, F = 250 N
- the friction force, backward, 
Given (1), we have

So the force of friction must be equal to the pull:

You could certainly have some good easy going carefree conversation with your sister or your cousin at dinner or at a movie, but relative dating is not an effective way to get serious and find a life partner.
Answer:
1.082 mm
Explanation:
From the question, we can see that we were given The following
Wavelength of the atoms, λ = 502 nm = 502*10^-9 m
Radius of the screen away from the double slit, r = 1.1 m
We know that Y(20) = 10.2 mm = 10.2*10^-3 m
d = (20 * R * λ) / Y(20)
d = (20 * 1.1 * 502*10^-9)/10.2*10^-3
d = 1.1*10^-5 / 10.2*10^-3
d = 1.082 mm
Therefore, we can say that the distance of separation between the two slits is 1.082 mm
In fact, entropy of an isolated system never decreases (2nd law of thermodynamics), unless some external energy is provided in order to "restore" order in the system and decrease its entropy.
(note that when external energy is added to the system, it is no longer "isolated").
*This is only true if the question is referring to a certain system within the universe. If we are considering the universe itself as the system, then this option is no longer correct, because no external energy can be provided to the universe, and since the universe is an isolated system, its entropy can never decrease. If we are considering the universe itself as the system, none of the options is true.