The temperature distribution in a fluid is given by T = 10x +5y, where x and y are the horizontal and vertical coordinates in meters and T is in degrees centigrade. Determine the time rate of change of temperature of a fluid particle traveling (a) horizontally with u = 20 m/s, v = 0, (b) vertically with u = 0, v = 20 m/s, (c) diagonally with u = 20 m/s, v = 20 m/s.