Recent content by rkjul

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...

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.

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...

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.

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...

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.

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...