Melting a snowball by throwing it at a wall

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AbsoluteZer0
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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



[itex]Q = mL[/itex]

[itex]E_k = \frac{1}{2} mv^2[/itex]

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:

[itex]mL = \frac{1}{2} mv^2[/itex]

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



[itex]Q = mL[/itex]

[itex]E_k = \frac{1}{2} mv^2[/itex]

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:

[itex]mL = \frac{1}{2} mv^2[/itex]

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

[itex]L = \frac{1}{2}v^2[/itex]

Edit:

I changed 334 j/g to 334000 j/kg and arrived at around 800 m/s
 
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