Answer:
Rt≅6377Km
Explanation:
Take a look at the image. The horizontal line is the horizon, and the angle α corresponds to the earth rotation during the 77 seconds.
With this information, we can know the value of α:
α = 
Since we have formed a rectangle triangle:
Solving for Rt:
Rt≅6377467m=6377Km
Answer: E) all of the above
Explanation:
Frequency is the number of vibrations in one second. It is also defined as the number of crests that pass a point in a given time.
The frequency and the wavelength has an inverse relationship.
Frequency is measured in cycles per second or Hertz(Hz).
The relationship between wavelength and frequency of the wave follows the equation:

where,
= frequency of the wave
c = speed of light
= wavelength of the wave
Thus all the given statements are true.
All you need is your science book
Answer:
Part a)

Part b)

Part c)
Since we know that the base area will remain same always
so here the length and width of the object is not necessary to obtain the above data in such type of questions
Explanation:
Part a)
As we know that when cylinder float in the water then weight of the cylinder is counter balanced by the buoyancy force
So here we know
buoyancy force is given as



Now we know that the weight of the cylinder is given as

now we have


Part b)
When the same cylinder is floating in other liquid then we will have

so we have


Part c)
Since we know that the base area will remain same always
so here the length and width of the object is not necessary to obtain the above data in such type of questions