As we know that in order to melt the copper we need to take the temperature of copper to its melting point
So here heat required to raise the temperature of copper is given as

We know that
melting temperature of copper = 1085 degree C
Specific heat capacity of copper = 385 J/kg C
now we have



now in order to melt the copper we know the heat required is

here we know that
L = 205 kJ/kg
now from above formula


now total heat required will be


As we know that

now we have

Answer:
5.65 times
Explanation:
60 db sound is equal to 60 phons sound when frequency is kept at 1000Hz.
But when the frequency of sound is changed to 100 Hz , according to equal loudness curves , the loudness level on phon scale will be 35 phons.
A decrease of 10 phon on phon- scale makes sound 2 times less loud
Therefore a decrease of 25 phons will make loudness less intense by a factor equal to 2²°⁵ or 5.65 less intense . Therefore intensity at 100 Hz
must be increased 5.65 times so that its intensity matches intensity of 60 dB sound at 1000 Hz frequency.
All form ions by losing electrons except oxygen.
Multiply 6 x 60 to get the frequency.