Answer:
I'm not really sure but I think it is
four
Due that the velocity is constant that means that friction force is equal to the force exert by you, otherwise the refrigerator will accelerate or decelerate and in both cases velocity will not be constant.
So then the friction force between refrigerator and floor is 150 Newtons.
Answer:
The wavelength is 
Explanation:
From the question we are told that
The wavelength of the first light is 
The order of the first light that is being considered is
The order of the second light that is being considered is
Generally the distance between the fringes for the first light is mathematically represented as

Here D is the distance from the screen
and d is the distance of separation of the slit.
For the second light the distance between the fringes is mathematically represented as

Now given that both of the light are passed through the same double slit

=> 
=> 
=> 
=> 
MEMORIZED E=h*v h=6.626x10-34J*s INFORMED v=7.21x1014S-1CALCULATE E=h*v E=(6.626x10-34J*s)*(7.21x1014s-1) The "s" cancels out. s-1=1/s so you get s/s so you are left with Solution 4.78 10-19 J OR .478 aJ <span>Apex - 467 nm ^.^ hopefully thats the correct thing</span>