6.4 Code Practice You should see the following code in your programming environment:

import simplegui

def draw_handler(canvas):
# your code goes here

frame = simplegui. create_frame('Testing', 600, 600)
frame. set_canvas_background("Black")
frame. set_draw_handler(draw_handler)
frame. start()
Using the code above to write a program that, when run, generates nested squares, similar to those below:

Nested squares

Your image should be slightly different from the one above (for example, the color of the lines, the spacing between squares, or the shapes could be different).

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.