Aman walke towards the bus stop 100 meters away at a constant velocity. he reaches the bus stop in 200 seconds. once at the bus stop, he sits for 500 seconds waiting for the bus. he then realizes he forgot something and runs home at a speed of 2.0 meters/second.

what is the velocity, displacement, and the time?

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?