Answer:
51.96 years
2) 30 million of years
Explanation:
First we must know the travel time of the ship seen from the earth. The spaceship travels at half the speed of light, this means that the amount of time the spacecraft must spend to travel the same distance is double compared to the light, that is 60 years.
Now due to the speed of the ship, we must take into account relativistic effects, such as time dilation, this is given by:

Where t is the time measured in the ship, t' is the time measured in the earth, inertially moving with velocity v.
Rewriting for t:

This is the amount of time it would take you reach the Whirlpool galaxy in the spaceship.
2) a light year is a measure of distance, which indicates the kilometers that light travels in a year. Thus, the light emitted by Whirlpool galaxy takes 30 million of years reaches our planet.
Answer:
3. relatively high temperature, about 10,000 K, so that significant numbers of electrons are excited from the ground state, n = 1, to the first excited state, n = 2, but not too many of them have been ejected completely from the atoms
Explanation:
If hydrogen absorption lines are very strong in the visible spectrum of a particular star that means the population of electron in n = 2 is very high so on being exited they absorb radiation in Balmer series and give rise to absorption spectrum. The average temperature required to excite electron in hydrogen atom from n=1 to n = 2 is 10000K .
Answer:
A. Mass
Explanation:
Inertia of an object is the resistance of the object to any change in its state of motion: it means that if an object is at rest, it tends to stay at rest for inertia (unless a net force acts on it), and if it is moving, it tends to continue moving with the same velocity, for inertia.
The inertia also describes how difficult it is to stop/accelerate an object, and it is directly proportional to the mass of the object: in fact, the larger the mass of an object, the more difficult it is to change its state of motion, and this means it has greater inertia.
Molten Mattet Seeps through the crust and forms new land.
It is fairly easy to build an electromagnet. All you need to do is wrap some insulated copper wire around an iron core. If you attach a battery to the wire, an electric current will begin to flow and the iron core will become magnetized. When the battery is disconnected, the iron core will lose its magnetism. Follow these steps.
Step 1 - Gather the Materials
One iron nail fifteen centimeters (6 in) long
Three meters (10 ft) of 22 gauge insulated, stranded copper wire
One or more D-cell batteries
Step 2 - Remove some Insulation
Step 3 - Wrap the Wire Around the Nail
Step 4 - Connect the Battery