You are attending the bonfire before the homecoming football game. The temperature of the air varies inversely with distance from the fire, so any circle centered at the fire is a constant temperature contour. However, the fire increases in intensity with time, so the temperature of the air at a given point increases with time. Assume that the temperature (K) of the air is given by T= 277 + 4t/r. Two students are following different paths as shown below. Path a moves tangentially to a circle whose radius is 2 m. Path b moves directly toward the fire. What is the rate of change of temperature in degrees per sec of the students at r = 2m and t = 10s?