Answer:
See the explanation.
Explanation:
The speeds of sound depend upon the temperature of the medium. As the temperature increased in the afternoon, the speed of sound increases. Then the time taken by reflected sound will be less than 0.1 sec in the afternoon. And to hear an echo the time gap between an original sound and reflected sound must be at least 0.1 sec. That is why the student could not hear the echo at all in the afternoon.
The pressure inside the bottle will build. When you push the cork inside of the bottle the air inside has less space to work with, so it bunches up, making the pressure build up as well.
-Seth
Answer:
B. -2
Explanation:
The total charge on an atom is the sum of all individual charges present in it. Therefore, the total charge on this atom is given by the following formula:
where,
q = total charge on atom = ?
= no. of protons in the atom = 15
= no. of electrons in the atom = 17
= no. of neutrons in the atom = 12
= charge on proton = +1
= charge on electron = -1
= charge on neutron = 0
Therefore,
Hence the correct option is:
<u>B. -2</u>
