Two atoms of the same element can have different numbers of protons
false
diff nos neutrons ... isotopes,
diff protons ... diff elements
Answer:
False
Explanation:
According to the big bang theory, matter was an infinitely small and very high density point which at one point exploded and expanded in all directions, creating what we know as our Universe, which also includes space and time . This happened about 13.8 billion years ago. Theoretical physicists have managed to reconstruct this chronology of events from 1/100 of a second after the Big Bang. After the explosion, while the Universe expanded, it cooled sufficiently and the first subatomic particles were formed: Electrons, Positrons, Mesons, Barions, Neutrinos, Photons among others. Today more than 90 particles are known. This theory solves many unknowns and is very well received by the scientific community, however there is still much to solve, for example, one of the great unsolved scientific problems in the expanding Universe model is whether the Universe is open or closed.
An attempt to solve this problem is to determine if the average density of matter in the Universe is greater than the critical value in Friedmann's model. The mass of a galaxy can be measured by observing the movement of its stars; multiplying the mass of each galaxy by the number of galaxies, it is seen that the density is only 5 to 10% of the critical value.
Answer:
20.62361 rad/s
489.81804 J
Explanation:
= Initial moment of inertia = 9.3 kgm²
= Final moment of inertia = 5.1 kgm²
= Initial angular speed = 1.8 rev/s
= Final angular speed
As the angular momentum of the system is conserved
The resulting angular speed of the platform is 20.62361 rad/s
Change in kinetic energy is given by
The change in kinetic energy of the system is 489.81804 J
As the work was done to move the weight in there was an increase in kinetic energy
Answer:
The correct answer is the Convex lens. An image is formed when a ray of light coming from a point intersects at another point. The image is formed by the real intersection of light. The image is formed by the virtual intersection of Light.
here is the site : textbook.com
Explanation:
Period of a mass on a spring is:
T = 2π√(m/k)
T is inversely proportional with the square root of k. So as the spring constant increases, the period decreases.
