Until a train is a safe distance from the station it must travel at 5 m/s. once the train is on open track it can speed up to 45 m/s. if it takes a train 8 seconds to reach 45 m/s, what is the acceleration of the train? (round your answer to the nearest whole number.) 4 m/s2 5 m/s2 6 m/s2 7 m/s2

The key to stability is feedback between the reservoir and the fluxes into and/or out of the reservoir. assume that the rate of outflow from a reservoir depends on the size of the reservoir according to the following relationship: outflow rate= k x (size of reservoir), where k is a constant. a reservoir of water has a volume of 5000 liters, and the rate of outflow at steady state is 25 liters per minute. what is k? (give both the numerical value and its units.) what is the residence time? what is the relationship between k and the residence time?

In a hydrogen molecule there are a total of four charges, 2 protons in the two nuclei, and 2 electrons. how many unique charge-pairs are there (without double counting)?

Anika asks eva to roll a basketball and then a bowling ball to her. which requires more force to roll, and why?