Question

A piece of metal slides on a rough floor.Its speed decreases from 10 m/s to 5 m/s due to friction.assume that half of the kinetic energy lost is absorbed by it in form of heat.Find the increase in its temperature if the specific heat capacity of the metal =375 J/$kg^{o}$C
(Hint:Kinetic energy=1/2 m$v^{2}$

Answer 1

Let m be mass of metal body)

change in Kinetic energy = KE initial - KE final = 1/2 m u² - 1/2 m v² 
                  = 1/2 * m * (10² - 5²) = 37.5 m  Joules

Heat energy given to the body is = 37.5 m Joules
                            = m s ΔT  = m * 375 * ΔT

          =>   ΔT = increase in temperature = 37.5/375 = 0.1°C