“Charged objects have an imbalance of charge - either more negative electrons than positive protons or vice versa. And neutral objects have a balance of charge - equal numbers of protons and electrons. The principle stated earlier for atoms can be applied to objects. Objects with more electrons than protons are charged negatively; objects with fewer electrons than protons are charged positively.
In this discussion of electrically charged versus electrically neutral objects, the neutron has been neglected. Neutrons, being electrically neutral play no role in this unit. Their presence (or absence) will have no direct bearing upon whether an object is charged or uncharged. Their role in the atom is merely to provide stability to the nucleus.”
Hope this helps a bit.
!! (Credits to The Psychics Classroom) !!
Answer:
Option D) 4A
Explanation:
As the cycle of the wave passes by, the amplitude gives the longest journey when the spot travels from the undistributed position. During each cycle the spot travels "Four times" .
Considering one of this cycle, if it begins to travel from it's undistributed position , there would be four movements i.e
* Upward movement through distance A
*Downward movement through distance A
*Downward again through distance A
*Upward through distance A.
Then it would travel back to its undistributed position held
Heat required to change the phase of ice is given by
Q = m* L
here
m = mass of ice
L = latent heat of fusion
now we have
m = 45 kg
L = 334 KJ/kg
now by using above formula


In KJ we can convert this as

so the correct answer is D option
For the first question, you got them right, for the two you left blank, initial(beginning) velocity: 2 m/s the final velocity is: 12 m/s