Problem on spacecraft
Assuming that ground stations are equally distributed on the Earth, how many ground stations are required to maintain constant contact with a spacecraft at 750 km altitude, and 72 degrees inclination?
Expert
Given:
θ (theta) = 72°, Perpendicular distance of spacecraft=750 km.
We know that, 1° = π/180 radian, Radius of earth=6400 km. So, 72°= (72*π)/180 radian, = 2*π/5Since,θ = Arc/Radius,
Therefore, Arc = θ*Radius, =2*π*750/5, = 300π
Circumference of earth = 2*π*Radius = 2*π*6400
No. of space station = Circumference of earth/2*Arc = (2*π*6400)/(2*300*π) = 21 space station (approx.)
What do you mean by the term density? Briefly explain it.
Explain Ideal gas laws or describe Boyle's law or Charle's law and Pressure law: Ideal gas laws: Boyle's law:
Becquerel: Bq (after A.H. Becquerel, 1852-1908) - The derived SI unit of the activity stated as the activity of radionuclide decay at a rate, on the average, of one nuclear transition every 1 s; it hence has units of s-1.
Biot-Savart law (J.B. Biot, F. Savart) - The law which explains the contributions to the magnetic field by an electric current. This is analogous to the Coulomb's law. Mathematically: dB = (mu0 I)/(4 pi r2) dl cross e
Fermat's principle: principle of least time (P. de Fermat): The principle, put onward by P. de Fermat that explains the path taken by a ray of light among any two points in a system is for all time the path which takes the least time.
Describe the reason in short why the length of a standard meter re-defined in the year of 1983?
Reflection law: For a wave-front intersecting a reflecting surface, the angle of incidence is equivalent to the angle of reflection, in the similar plane stated by the ray of incidence and the normal.
Permittivity of free space: electric constant; epsilon_0: The ratio of the electric displacement to the intensity of the electric field generating it in vacuum. It is equivalent to 8.854 x 10-12 F/m.
Hoop conjecture (K.S. Thorne, 1972): The conjecture (as so far unproven, although there is substantial proof to support it) that a non-spherical object, non-spherically compressed, will only form a black hole whenever all parts of the
Ergosphere: The area around a rotating black hole, among the event horizon and the static limit, where the rotational energy can be removed from the black hole.
18,76,764
1927289 Asked
3,689
Active Tutors
1412484
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!