### Practice exam key

Hello everyone-

I've posted a key to the hot air balloon problem we did yesterday, as well as to the practice exam we worked on today.

I managed to pretty badly mangle things on the second problem of the practice exam today, as several of you pointed out. I over-specified information in the thermodynamic cycle problem, so that the problem was internally inconsistent. I've revised the problem and written up a solution. I rushed preparing the problem this afternoon before class and I didn't think it through thoroughly. I apologize for the oversight and hope that the explanation in the key will assure that you come out of the practice exam experience more, rather than less, prepared for the exam.

With regards to studying: The cumulative multiple choice part of the exam covers kinematics and linear dynamics (no rotational dynamics or statics). It really focuses on your conceptual understanding of concepts like velocity, acceleration, force, momentum, energy, and the relationships between these. It doe not call for a calculator.

The rest of the exam is a bit more traditional. It will cover fluids, temperature and heat (and the relationship between them), the First Law of thermo and ideal gases. One of the problems asks for an explanation rather than a calculation; the rest are fairly straightforward (and well-posed) calculation problems.

See you Monday, 10:00, in MWAH 195!

jay-