The weight of anything in any place is
(mass of the thing) x (acceleration of gravity in that place).
-- On Earth, the acceleration of gravity is about 9.807 m/s²
Weight of 19 kg of mass is (19 kg) x (9.807 m/s²) = <em>186.3 newtons</em>
-- On the Moon, the acceleration of gravity is about 1.623 m/s²
Weight of the same 19 kg of mass is (19 kg) x (1.623 m/s²) = <em>30.8 newtons</em>
The answer is: none of the above.
Explanation:
When light reflects from a surface, the frequency, wavelength, and speed do not change. They remain the same.
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.