Answer:
462 nm
Explanation:
Given: width of the slit, d = 5.6 × 10⁻⁴ m
Distance of the screen, D = 4.0 m
Fringe width, β = 3.3 mm = 3.3 × 10⁻³ m
First dark fringe means n =1
Wavelength of the light, λ = ?
B. NaCl
All of the other answers contain a 2 or a number in general. Metals do not form covalent bonds. Alkali-halide salts are Ionic compounds. Ionic compounds form from bonding a metal and a non metal. Covalent bonds are formed by bonding non metals.
Answer:
The skidding distance would be doubled
Explanation:
When the truck applies the brakes and slows down, its motion is a uniformly accelerated motion, so its skidding distance can be found by using the suvat equation

where
v = 0 is the final velocity (zero since the truck comes to a stop)
u is the initial velocity
a is the acceleration
s is the skidding distance
The acceleration can also be written as

where F is the force applied by the brakes and m the mass of the truck. Substituting into the previous equation,

We see that the skidding distance is proportional to the mass: therefore, if the mass of the truck is doubled, the skidding distance will double as well.
Answer:
In standard GR, nothing exists at the center of a black hole. The center of a black hole is a singularity, and because GR fails at that point it is simply removed from the manifold. That means that the singularity is not part of spacetime.
To answer your question more realistically, we believe that GR is an approximate theory that fails well before you reach the center. Unfortunately, we have no good alternative theory with which to answer the question in the region where GR fails. We simply don’t have any data from that regime and it is very hard to formulate a good theory without data. So there very well could be time at the center, but we simply don’t have a good way to even guess.