The frequency of a sound wave is the number of cycles of a sound wave per second or Hertz (Hz). The frequency can be calculated by dividing wavelength by time (Figure 1.3). A small wavelength will yield a higher frequency, whereas a larger wavelength will yield a smaller frequency.
the second level will have 8 electrons.
Answer:
The speed of the aircraft relative to the ground is 606.9 
Explanation:
x-y coordinate system:
x is Positive due East direction. Similarly y is Positive due North Direction.
Now let us Decompose each vector into x-y
500 km/h due east = (500, 0)
120 km/h at 30 degree north of east
= 
= 
= 
Adding the vectors.
=
=
=
=
= (603.8, 60)
Returning back to polar form
Magnitude = 
Answer:
The rods remain radioactive for thousands of years, so storage is a difficult problem.
Explanation:
Fuel rods represents the main element of the reactor core of a nuclear power plant.
They contain uranium-238 (U-238) enriched with uranium-235 (U-235), which is very unstable; when the nuclei of uranium absorb slow neutrons, they undergo nuclear fission, breaking apart and releasing huge amounts of energy.
In the process, several neutrons are released alongside with other products, and when they are slown down, they can be absorbed by other nuclei of uranium, further inducing more fissions.
The half-life of U-238 is 4.5 billion years, while the half-life of U-235 is approx. 700 million years: this means that the fuel rods remain highly radioactive for a very long time. Therefore, it is necessary to properly dispose them in a safe place where they do not represent a hazard. For instance, fuel rods: for example, they can be placed in sealed containers (built using concrete/steel to shield from the radiation) and buried underground.
