Question

an iron mass falls from a height of 1km on the ground.if all the energy is converted into heat, the rise of temperature of mass will be​

Answer 1

let mass of iron ball = m

At height = 1km =1000m, 

total energy = potential energy = mgh = 1000*9.8*m = 9800m J =9.8m kJ

When all energy is converted into heat and used in raising the temperature of ball,

Specific heat of iron(s) = 0.1 kcal/kg C = 0.42 kJ/kg C 

Let change in temperature = ΔT

ms(ΔT) = mgh

⇒ms(ΔT) = 9.8m

⇒ s(ΔT) = 9.8

⇒ 0.42(ΔT) = 9.8

⇒ ΔT = 9.8/0.42 = 23.3 degree celsius