What does Newton's third law say about why momentum is conserved in collisions? Equal forces act in equal times, so the change in momentum for both objects must be equal. Unequal forces act for unequal times, so the change in momentum for both objects must be unequal. Unequal forces act for unequal times, so the change in momentum for both objects must be equal. Equal forces act for unequal times, so the change in momentum for both objects must be equal.

you need to have a picture of the atom that way we can answer it

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.