The length ℓ, width w, and height h of a box change with time. at a certain instant the dimensions are ℓ = 7 m and w = h = 9 m, and ℓ and w are increasing at a rate of 8 m/s while h is decreasing at a rate of 6 m/s. at that instant find the rates at which the following quantities are changing. (a) the volume. 774 correct: your answer is correct. m3/s (b) the surface area. 352 correct: your answer is correct. m2/s (c) the length of a diagonal. (round your answer to two decimal places.) 5.09 correct: your answer is correct. m/s