Bus travels 280km south along a straight path with an average velocity of 88km/hr to the south. Bus stops for 24 min. Then travels 210km south with an average velocity of 75km/hr to the south. How long does the total trip take? What is the average velocity for the total trip?

Thank you! 1) What is the shortest possible time in which a bacerium could travel a distance of 8.4cm across a Petri dish at a constant speed of 3.5mm/s? 2)Child pushing shopping cart speed of 1.5m/s. How long will it take this child to push the cart down an aisle with length of 9.3m? 3) An athlete swims from north end to the south end of a 50.0m pool in 20.0 sec and makes the return trip to the starting position in 22.0sec. a.) what is the average velocity fot the first half of the swim? b.) what is the average velocity for the second half of the swim? c.) what is the average velocity for the roundtrip? 4) Two students walk in the same direction along a straight path, at a constant speed one at 0.90m/s and the other at 1.90m/s. a.) assuming that they start at the same point and the same time, how much sooner does the faster student arrive at a destination 780m away? b.) How far would the students have to walk so that the faster student arrives 5.50min before the slower student? Those are the only problems I have not done yet, I would really appreciate if you could just help me use the correct equation, and I then I could solve it.