Thermo problem

  1. My teacher gave us this problem before break in a packet and we basically had to teach ourselves how to do problems like this, and unfortunately, I'm no natural at physics and I might only just have the right equation to apply to the problem yet I have absolutely no understanding of how to use the equation to solve the problem, and I don't even know if its the right equation at all. Basically: FAIL x 1000

    The problem:

    A 2.00 kg block has a specific heat of 115 J/ (kg x K). It falls from rest through a distance of 100.0 meters to the earth's surface. If half of the potential energy lost by the fallen block when it hits is converted to internal energy of the block, what is the temperature change of the block?

    I lied. I actually know of two equations to use, and they are Q = mcΔt and Δke + Δpe + ΔU = Q - W where W is work and U is the change in internal energy (?) But I have zero knowledge of how to use these eqns unfortunately.

    If someone could even at least point me to a youtube video that would teach me this stuff, it would be as meaningful to me as a grand unifying theory's discovery would be to physics.

  2. jcsd
  3. SammyS

    SammyS 8,197
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Your teacher may be trying to get you practice problem solving, rather than blindly plugging into equations.

    The words above in red should allow you to come up with your own equation.

    The change internal energy of the block will heat up the block, as given by Q = mcΔT.
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