C is probably the correct one
Answer:
Use of telemetry and radar astronomy
Explanation:
An astronomical Unit (AU) is a unit of measuring distances in outer space, which is based on the approximate distance between the earth and the Sun.
After several years of trying to approximate the distance between the Sun and the Earth using several methods based on geometry and some other calculations, advancements in technology made available the presence of special motoring equipment, which can be placed in outer space to remotely monitor and measure the position of the sun.
The use of direct radar measurements to the sun (radar astronomy) have also made the determination of the AU more accurate.
A standard radar pulse of known speed is sent to the Sun, and the time with which it takes to return is measured, once this is recorded, the distance between the Earth and the Sun can be calculated using
distance = speed X time.
However, most of these means have to be corrected for parallax errors
Answer:




Explanation:
r = Radius of disk = 7.9 cm
N = Number of revolution per minute = 1190 rev/minute
Angular speed is given by

The angular speed is 
r = 2.98 cm
Tangential speed is given by

Tangential speed at the required point is 
Radial acceleration is given by

The radial acceleration is
.
t = Time = 2.06 s
Distance traveled is given by

The total distance a point on the rim moves in the required time is
.
Answer:
100years later
Explanation:
Because the lights will arrive at world after 100 years later.
It is most likely true that there was a lower concentration of salt in the water than in the cells because when blood cells are put in a hypotonic solution such as pure water, the little to no salt concentration in the water causes the cells to swell and burst. This would occur because the water would try to dilute the solution inside of the blood cell and which would, therefore, cause it to burst. Hope this helps!