Which three sensors can a robot use for detecting or measuring environmental conditions? 1. a pressure sensor to detect physical contact between objects
2. a thermal sensor to measure the temperature of a component
3. a light sensor to measure the intensity of light sources
4. an ultrasonic sensor to measure distances to objects
5. a sound sensor to detect noise levels or recognize speech

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]