a car travel uniformly speed of 30 km/h for 30 minutes and then at uniform speed of 60km/h for next 30min calculate the average speed of car​

An ideal otto cycle has a compression ratio of 10.5, takes in air at 90 kpa and 40°c, and is repeated 2500 times per minute. using constant specific heats at room temperature, determine the thermal efficiency of this cycle and the rate of heat input if the cycle is to produce 90 kw of power.