Recent content by rkjul

  1. R

    Terminal velocity of a coffee filter

    Homework Statement You drop a single coffee filter of mass 1.2 grams from a very tall building, and it takes 47 seconds to reach the ground. In a small fraction of that time the coffee filter reached terminal speed. (a) What was the upward force of the air resistance while the coffee...
  2. R

    Energy Transfer in a Water and Aluminum Pan System

    I calculated two values of mC*delta T, one for the water (100*4.2*8.6) and one for aluminum (375*0.9*8.6) and added those together and set that equal to Q+1400. I got Q=5115 (same answer as you) and it's incorrect.
  3. R

    Energy Transfer in a Water and Aluminum Pan System

    Homework Statement 100 grams of boiling water (temperature 100° C, heat capacity 4.2 J/gram/K) are poured into an aluminum pan whose mass is 375 grams and initial temperature 24° C (the heat capacity of aluminum is 0.9 J/gram/K). (a) After a short time, what is the temperature of the water...
  4. R

    Two protons moving toward each other

    Thanks...that's what I did. I took that number and then used that in the equation for electric potential energy to obtain the distance. Sometimes I have a habit of making silly mistakes/overthinking things.
  5. R

    Two protons moving toward each other

    Homework Statement Two protons that are very far apart are hurled straight at each other, each with an initial kinetic energy of 0.16 MeV, where 1 mega electron volt is equal to 10^6*(1.6*10^-19) joules. What is the separation of the protons from each other when they momentarily come to a...
  6. R

    Force question involving an asteroid and spacecraft

    I got it by using deltap=mass*deltav and solving for deltav, then multiplying by deltat (4 days and doing appropriate coversion). I had been working on this assignment for a long time. It's funny how you can sometimes get a brain cramp over fairly simple things.
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    Force question involving an asteroid and spacecraft

    Homework Statement This is a 5-part problem. In June 1997 the NEAR spacecraft ("Near Earth Asteroid Rendezvous"; see http://near.jhuapl.edu/), on its way to photograph the asteroid Eros, passed within D=1200 km of asteroid Mathilde at a speed of 10 km/s relative to the asteroid...
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