Answer:
The poles of the magnetic field generated around the armature are attracted to the opposite poles of the permanent magnet. As the opposite poles align, the commutator reverses the current direction so like poles are aligned and the armature continues to spin.
Explanation:
Answer:
D.
Explanation:
But this just happen for big stars, like more than 20x the Sun mass.
Shortly: A nebula is a cloud of gas and dust, the material starts to be acummuleted and became a protostar (is like a big planet, almost a star). With enought mass this is a star, burn hydrogen and transform it in Helium.
This occurs in Main Sequence, is about almost all the life time of a star. Then starts the lack of hydrogen. Gravity compress everything, pressure goes up and heat all. Too much energy, Helium get burned and the star grews fast, became a Red Giant. Time pass and the fuel is over, no more making fusion, gravity compress the star, too much strenght, colapses, neutron star.
If it have pretty mass, ok. If have more than like 2x Sun mass, became a blackhole.
Greater water pressure acts on the bottom than on the top
Answer:
Explanation:
From the question we are told that
Nucleus diameter 
a 12C nucleus
Required kinetic energy 
Generally initial speed of proton must be determined,applying the law of conservation of energy we have
where
=initial kinetic energy
=final kinetic energy
=initial electric potential
=final electric potential
mathematically
where
=distance b/w charges
=nucleus charge 
=constant
=proton charge
Generally kinetic energy is know as
Therefore
Generally equation for radius is 
Mathematically solving for radius of nucleus
Generally we can easily solving mathematically substitute into v_1
Therefore the proton must be fired out with a speed of
Galileo Galilei is one of the key figures in the history of Science, being the first to apply the experimental-mathematical scientific method. He carried out experiments and careful observations in kinematics (his studies on the trajectory of projectiles are famous) and dynamics (it should be noted his careful experiments with inclined planes), establishing the first law of Dynamics (which Newton will later collect and refine in his Principles); and in Astronomy, with which he could unequivocally support the heliocentric theory.
His experiments were addressed by methodologies that allowed him to precisely find his mathematical calculations and to verify theories he was developing over time. His manuscripts were key to disseminate the applied method and extrapolate them to other scientific areas.
Therefore the correct answer is C.
