21. light changes its direction when travelling through a new medium because denser mediums have a higher angle of refraction.
The speed of a proton after it accelerates from rest through a potential difference of 350 V is .
Initial velocity of the proton
Given potential difference
let's assume that the speed of the proton is ,
Since the proton is accelerating through a potential difference, proton's potential energy will change with time. The potential energy of a particle of charge when accelerated with a potential difference is,
Due to Work-Energy Theorem and Conservation of Energy - <em>If there is no non-conservative force acting on a particle then loss in Potential energy P.E must be equal to gain in Kinetic Energy K.E</em> i.e
If the initial and final velocity of the proton is and respectively then,
change in Kinetic Energy
change in Potential Energy
from conservation of energy,
so,
To read more about the conservation of energy, please go to brainly.com/question/14668053
When a perfume bottle is opened, some liquid changes to gas and the fragrance spreads around the room because gases do not have a definite volume.
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