As the driver steps on the gas pedal, a car of mass 1150 kg accelerates from rest. During the first few seconds of motion, the car's acceleration increases with time according to the expression below, where t is in seconds and a is in m/s2. a = 1.11 t - 0.210 t2 + 0.240 t3 (a) What is the change in kinetic energy of the car during the interval from t = 0 to t = 3.20 s? J (b) What is the minimum average power output of the engine over this time interval? W (c) Why is the value in part (b) described as the minimum value?

This is important 1. what happens to the speed of molecules in water vapor when it condenses to form a liquid? (2 points) the molecules slow down. the molecules speed up. the molecules slow down and then speed up. the molecules speed up and then slow down. 2. how might human activities change to compensate for a decrease in water supplies? (2 points) humans might build a factory. humans might build drainage systems. humans might extract more water from the ground. human behavior does not change because of the water cycle. i'll be grateful if anyone can answer these 2 questions !