Calculate the height that a block of ice at 0°C must be dropped to completely melt upon impact.?

Answer 1

If the ice is at 0 degrees, and we assume all of the energy is converted to heat, then

decrease in potential energy = energy required to melt ice

mgh = mL

where L is the specific latent heat of ice

m X 9.8 X h = m 337000

h = 337000 / 9.8 = approx 33700 m

Some previous answerers had neglected to convert kJ/kg into J/Kg

Answer 2

That's one of these really unrealistic questions some teachers like to ask.
Sure you could calculate at which height the potential energy of the ice is as high as the energy you need to completely melt the ice. But in practice that hight would not even be remotely sufficient to actually melt the ice because most of the energy is not used to melt the ice but goes somewhere else.
Let's calculate it anyway.
The potential energy is supposed to be equal to the enery needed to melt the ice.
m*g*h=335kJ/kg * m
h=335kJ/g = 33.5m

Answer 3

If it drops from a height h, the potential energy is mgh Which will also be the kinetic energy when it touches the floor. If all this gets converted into heat, the amount of heat is mgh/J (J is Joule's constant) This should be equal to mL, where L is the latent heat of fusion of ice. mL = mgh /J >> h = LJ/g

Answer 4

look up the energy to melt ice, by example 1 kg,
the energy of the collision with the surface will melt the ice, height, weight and speed , success!

Answer 5

9.8*h = 80*4.184

or h = 34.155 m