Recent content by runningphysics

I figured it out. What needs to happen the mass for Q1 needs to be the total mass divided by 2. The Q2 mass needs to be the total mass. This is because 1/2 of the water is being boiled off, but the total amount of water needs to reach the 100 degrees Celsius.

I tried using the equation Q'*t= Q1+Q2. Where Q' is the energy of the reactor aka 200,000 kJ and t is the time. Take Q1 to be (1/2m*2257) and Q2 to be (1/2m*4.184*90). The 90 is the change in temperature for the phase change to occur from liquid water to gas, or boiling. Plugged everything in...

I have no clue how to do the problem. I created a free body diagram for each block. I assume that it is simpler than I am making it out to be.

I tried splitting the forces up into F1 and F2 making Newtons second law equation into F1+F2=ma. Then I added over the the first force given. multiply the mass to the acceleration terms to get F2= (m*ai + m*aj) - F1

OK, I tried it out and it works! I was confused with the wording of the question, but setting the x equation, x=-.65t^2 i + 14t i, equal to zero and using the quadratic worked. Thanks for your help!

I'm not sure where to start, when I tired using integration of the initial equation to get pos(t)=-.65t^2 i + .13t^2 j + 14ti +13tj but after separating each component, i and j, and setting j equal to zero I got 0 or -100 seconds which doesn't seem like a reasonable answer.