Acircular disc with a radius of gyration of 200 mm and a mass of 15 kg is rotating in the clockwise direction with an angular velocity of 5 radians per second. from the time t=0 seconds if the disc is subjected to a counterclockwise moment of 9t, where t is the time in seconds, deternmine the direction and magnitude of angular velocity of the disc at time t=10 seconds.

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]