physics question

Question

A 54- ice-skater moving at  6.5 m/s glides to a stop.

 Assuming the ice is at 0 celsius

 

and that 50% of the heat generated by friction is absorbed by the ice, how much ice melts? The heat of fusion for water is 

.

Answer 1

Lilly B,

Without stated units, I can only give you hints.

Using mass and average velocity of the skater (6.5/2m/s), determine the change in KE. (KE=0.5•m•v²)

then use 50% of this and equate it to latent heat of fusion of ice.

50%KE = ml (calculate m using l, the specific latent heat of fusion of ice which is a known quantity that you should be able to look up online. Pay attention to units)

If you need more clarification with this or any other problem, feel free to ask me. Please keep in mind that units in physics are very important and can be a major source of errors. Look the NASA mars probe story from 2000-2001. Mr. A