Answer:
a) 4500 cycles b) 0.0667s c) 6.67s
Explanation:
a) 15 Hz= 15 cycles/ s
5 mins= 300s
15 cycles/s * 300s= 4500 cycles
b) Period= 1/ frequency
Period= 1/ 15 cycles/s
Period= 0.0667s
c) Period * number of revolutions= time
0.0667 * 100= 6.67s
Answer:
Amplitude is decreased by a factor of
if intensity is decreased by a factor of 3.
Explanation:
Intensity of a sound wave is directly proportional to the square of its amplitude.
Therefore, if intensity is
and amplitude is
, then
, where,
is constant of proportionality.
Now, if intensity of sound wave is decreased by a factor of 3. So,
New intensity is, 

Plug in
for
. This gives,

Therefore, amplitude is decreased by a factor of
.
Answer:

Explanation:
In all atoms, the number of protons = number of electrons, as a result the atom is neutral. Losing or gaining electrons will make the atom electrically charged and we call an electrically charged atom an ion.
Ca 2+ would be the symbol because losing two negative electrons makes calcium's nucleus more positive by two protons.