1. a 1000-kg car moves as speed from 10 m/s to 30 m/s in 20 seconds. what is the average speed? what is the acceleration? what is the average force acting upon it? if the car turns along a circle at speed 5 m/s around a curve 30 meters in radius, how big the centripetal force is needed?

8.29 two streams containing pyridine and acetic acid at 25°c are mixed and fed into a heat exchanger. due to the heat-of-mixing effect, it is desired to reduce the temperature after mixing to 25°c using a stream of chilled ethylene glycol as indicated in the diagram. calculate the mass flow rate of ethylene glycol needed. the heat capacity of ethylene glycol at these conditions is approximately 2.8 kj/(kg k), and the enthalpy change of mixing (δmixh) is given below.