A nail driven into a board increases in temperature.
If 60.0% of the kinetic energy delivered by a 1.80 kg hammer with a speed of 7.80 m/s is transformed into heat that flows into the nail and does not flow out, what is the increase in temperature of an 8.00 g aluminum nail after it is struck 10.0 times? (answer in degrees C please)Physics problem: nail driven in board?
use this formula
60/100 * 1/2 * 1.8 * 7.8^2 * 10 = 8 * Cp * delta T
you should know the Cp of Al to find the delta T in J/gK, i will not do it for you.Physics problem: nail driven in board?
Kinetic energy of hammer = 1/2 mv虏 = 1/2 (1.8)(7.8虏)
60 % of kinetic energy is delivered per hammer strike.
Energy delivered per strike = 60% of [1/2 (1.8)(7.8虏)]
= 0.6 X [1/2 (1.8)(7.8虏)]
= (0.3)[(1.8)(7.8虏)]
There are 10 strikes so total energy delivered is
10 X (0.3)[(1.8)(7.8虏)]
= 3[(1.8)(7.8虏)]
= 328.536 Joules.
Equate this to energey absorbed by nail mc螖T
Where m = mass of nail = 0.008 kg
c = specific heat capacity of aluminium
螖T = temperature rise
mc螖T = 328.536
螖T = 328.536 / mc
螖T = (328.536) / (0.008c)
Just plug in the value for c and you have your answer.
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