END; include ("common_short.php"); physics_header("",""); print <<Physics H133: Problem Set #\$ps_num Here are some hints, suggestions, and comments on the problem set.

## Two-Minute Problems

Remember to give a good explanation, no longer than two sentences.

1. T1T.3: Does the measurement allow for unique conclusions? Is it calibrated?
2. T1S.2: Imagine using 1/T instead of T. Would this be allowed?

## Chapter T1 Problems

• T1S.3: Draw a good picture and then apply H131 physics: for the cylinder to stay at rest, the total force acting on it (in the vertical direction) must be zero. Include the forces from pressure on top and bottom, plus the gravitational force.
• T1S.8: Follow the logic given in the problem statement. (a) How are changes in U and in T related? (b) Simply plug in and do the algebra to solve for T_f. (c) Take the corresponding limit and interpret your result. Does it make sense?
• T1S.9: Given the results of T1S.8 above, this is simple plug and chuck.
• T1R.1: Draw force diagrams. Which forces act on the cap sealing the top, which act on the card at the bottom? Is anything moving? What is the condition that insures that the card is not moving and the water is not falling out?
• T1A.1: Note that Equation (T1.11) implicitly defines z=0 as the surface of the earth. The top of the atmosphere is then z=infinity. You want to apply Equation (T1.7) from problem T1S.3 to a column of air that is dz thick (i.e., infinitesimally thin). Then (T1.7) gives you dP = P(z+dz) - P(z) in terms of rho, g, and dz. Integrate z from 0 to infinity to get the pressure difference P(infinity) - P(0) = -P(0), and use values on the inside front cover for P(0) and rho(0).