Ireally need some with this 20 points and brainliest to the person who me. 22) mary started at point a. she walked to point o and then stopped at point b. what is mary’s total displacement from her starting point? what is the total distance that she walked from her starting point? if she walked 700 meters in 5 minutes, what was her speed? (s=d/t)

Athin electrical heater is inserted between a long circular rod and a concentric tube with inner and outer radii of 20 and 40 mm. the rod (a) has a thermal conductivity of ka = 0.15 w/(m*k), while the tube (b) has a thermal conductivity of kb = 0.8 w/(m*k) and its outer surface is subjected to convection with a fluid of temperature t= -15°c and heat transfer coefficient 60 w/(m2 *k). the thermal contact resistance between the cylinder surfaces and the heater is negligible. (a) determine the electrical power per unit length of the cylinders (w/m) that is required to maintain the outer surface of cylinder b at 15°c. (b) what is the temperature at the center of cylinder a?