Question

A nail driven into a board increases in temperature.If 64.0 % of the kinetic energy delivered by a 1.80 kg hammer with a speed of 8.00 m/s is transformed into heat that flows into the nail and does not flow out, what is the increase in temperature of an 7.65 g aluminum nail after it is struck 10 times? (Celsius)

Answer 1

Given is:-

Mass of hammer   mass of nail   or

speed of hammer is v=8 m/s percentage of energy delivered from hammer to nail is = 64%

Now we have to apply the principle of conversation of energy, as we know that energy never looses, it just changes from one form to other form. It is clearly mentioned that heat flows in nail dosen't comes out.

Thus the kinetic energy of the hammer is

by putting all the values in above equation, we get

now we have to calculate the 64% of this energy, which is going to heat the nail

the nail is struked 10 times, therefore the total energy is

this kinetic energy heats up the nail

therefore

specific heat of aluminium is = 904 J/kg-K

thus

Thus the increase in the temperature due to transfer of kinetic energy is 55.55 degree celcius or Kelvin