Melting a snowball by throwing it at a wall

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To determine the speed required to completely melt a snowball thrown at a wall, the kinetic energy formula and the latent heat equation are used. The key equation derived is L = (1/2)v^2, where L represents the latent heat. The mass of the snowball is not needed in calculations since it cancels out, simplifying the problem. After converting the latent heat from joules per gram to joules per kilogram, a speed of approximately 800 m/s is calculated. This solution effectively demonstrates the relationship between kinetic energy and the energy required for phase change.
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Homework Statement



You throw a snowball at 0.0 Celsius at a brick wall. If you want it to melt completely, how fast will you have to throw it?

Homework Equations



Q = mL

E_k = \frac{1}{2} mv^2

The Attempt at a Solution



I initially reasoned that you would use Q = mL to find the energy needed to melt it and then substitute that into the Kinetic energy formula, giving:

mL = \frac{1}{2} mv^2

However, I am given no information regarding the mass of the snowball and haven't figured out a method to find that mass.
Any suggestions?

Thanks,
 
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Why do you need mass when it cancels out in the equation you formed? :confused:
 
AbsoluteZer0 said:

Homework Statement



You throw a snowball at 0.0 Celsius at a brick wall. If you want it to melt completely, how fast will you have to throw it?

Homework Equations



Q = mL

E_k = \frac{1}{2} mv^2

The Attempt at a Solution



I initially reasoned that you would use Q = mL to find the energy needed to melt it and then substitute that into the Kinetic energy formula, giving:

mL = \frac{1}{2} mv^2

However, I am given no information regarding the mass of the snowball and haven't figured out a method to find that mass.
Any suggestions?

Thanks,

Just assume that mass equals 1.
 
Pranav-Arora said:
Why do you need mass when it cancels out in the equation you formed? :confused:

Ah!
I didn't notice that. Thanks.

I'm now at

L = \frac{1}{2}v^2

Edit:

I changed 334 j/g to 334000 j/kg and arrived at around 800 m/s
 
Last edited:
If you want your working checked, please post it.
 
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