Which statement best describes how waves impact beaches? question options: a. beaches change over time as waves move further up the shore. b. beaches change little over time as waves follow the same patterns year after year. c. beaches change little over time as wind patterns stay the same. d. beaches are always changing due to factors such as waves adding and eroding sand.

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.