A piece of substance of specific heat capacity 450Jkg\(^{-1}\)k\(^{1}\) falls through a vertical distance of 20m from rest. Calculate the rise in temperature of the substance on hitting the ground when all its energies are converted into heat. [g = 10ms\(^{-2}\)]
A
\(\frac{2}{9}\)ºC
B
\(\frac{4}{9}\)ºC
C
\(\frac{9}{2}\)ºC
D
\(\frac{9}{4}\)ºC
Verified Correct Answer: B.
Physical Principles & Numerical Solution
Using the law of conservation of energy
mc\(\bigtriangleup\theta\) = mgh
\(\bigtriangleup\theta\) = \(\frac{gh}{c} = \frac{10 \times 20}{450} = \frac{4}{9}\)ºC
Source: WAEC / JAMB / NECO Classroom Archive (Record #60777)