Why Does Hot Water Freeze Faster Than Cold Water?

  • Thread starter Thread starter Unredeemed
  • Start date Start date
AI Thread Summary
The discussion centers on the Mpemba effect, where hot water can freeze faster than cold water. Participants acknowledge that the exact reasons for this phenomenon are not fully understood. Suggestions include formulating hypotheses and designing experiments to explore potential explanations. The conversation emphasizes the importance of inquiry and observation in scientific exploration. Engaging with the Mpemba effect can lead to deeper insights into thermodynamics and water properties.
Unredeemed
Messages
120
Reaction score
0

Homework Statement


For my physics homework I'm supposed to make "5 intelligent and observant questions about the Mpemba effect." but I don't even know why it happens! Can anyone help me out?


Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
AFAIK no one knows exactly why the Mpemba effect occurs. I suggest you try to come up with explanations and ways to test them,
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...

Similar threads

Back
Top