9 A substance fills a jar. A scientist transfers the substance to a 2
liter bottle. The substance fills the entire space of the 2 liter bottle.
What is the state of matter of the substance?

Liquid

Explanation:

The substance had appears to have a fixed volume but took the shape of the bottle it was transferred to.

If the substance doesn't have the same volume, the answer would be gas.

gold is my favorite solid.

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.