1. Identify the flaw in the way Maria set up her experiment. A. She did not take pictures.
B. She did not wait long enough.
C. She did not measure the temperature.
D. She did not mix the substances well enough.
2. Which of the following describes Maria making an observation?
A. Maria measured the compounds.
B. Maria let the test tube sit for one minute.
C. Maria wrote her results in her lab notebook.
D. Maria saw that bubbles formed on the metal in in mixture.

c and d, because if maria did not measure the temperature then the experiment would not work and if you observe something that is some thing you see.

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.