1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Find the mass of ice that melts during the hit.

  1. May 23, 2015 #1
    1. The problem statement, all variables and given/known data
    The sphere of lead with mass 2kg and velocity 20m/S hits a block of ice and is stuck in it. Find the mass of ice that melts during the hit. The initial temperature of the sphere is 293 K and c=128J/kg*grade.
    2. Relevant equations
    m1v1=m2v2

    3. The attempt at a solution
    I thought to use the formula but what is the v of ice?
     
  2. jcsd
  3. May 23, 2015 #2
    The lead sphere had kinetic energy before collision, but none afterwards. How much kinetic energy was this? What form has this energy been converted to?
    Set up an equation with the total initial and final energies set equal to each other.
     
  4. May 23, 2015 #3
    Ek=400J
    Next should I write mcT=Ek? How can I find the difference in ice temperature?
     
  5. May 23, 2015 #4

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    The ice doesn't change temperature. It just turns to water at the same temperature.

    Is that the right equation in this situation?
     
  6. May 23, 2015 #5
    Hmmm, I think the initial temperature of the ice does matter. The question does not specify that the ice is at 0 degrees Celsius. If it is at any other lower temperature, some of the energy from the 400J would bring it to the melting point and the remaining would convert the ice to water (the latent heat of fusion), so the initial temperature will clearly affect the mass of ice that melts. I think the question is incomplete.
     
  7. May 23, 2015 #6

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    You are correct. I didn't notice the initial temperature of the ice wasn't specified.

    I agree the question is incomplete. You can't solve it unless you assume the ice is at zero.
     
  8. May 23, 2015 #7
    You had better get used to having incomplete data in life. Intelligent assumptions are a part of many problem solutions.
     
  9. May 23, 2015 #8
    The answer is 16.5 g, if it helps
     
  10. May 23, 2015 #9
    So, what are all the sources of energy available to melt the ice?
     
  11. May 23, 2015 #10
    The sphere with its energy
     
  12. May 23, 2015 #11
    And what two types of energy are available in the lead shpere?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Find the mass of ice that melts during the hit.
  1. Ice melting (Replies: 1)

  2. Melting ice (Replies: 3)

  3. Melting ice (Replies: 2)

  4. Melting Ice (Replies: 4)

  5. Ice Melting (Replies: 3)

Loading...