1. A train leaves the station in such a way that the distance it has moved along the track is 2012 s(t) 1+t where t is measured in seconds and s in metres. Find the average speed between t = 0 and t 4 s. Find the instantaneous speed at t= 9 s. 2. A bus draws away from a bus stop and travels along a straight road until it gets to the next stop. Between the two stops, the distance it has travelled is s(t) t(150-t), 1000 where t is measured in seconds from the departure time, and s in metres. What is its speed at the second stop? At what time does it reach the second stop? How far away is the second stop?

1. A train leaves the station in such a way that the distance it has moved along the track is 2012 s(t) 1+t where t is measured in seconds and s in metres. Find the average speed between t = 0 and t 4 s. Find the instantaneous speed at t= 9 s. 2. A bus draws away from a bus stop and travels along a straight road until it gets to the next stop. Between the two stops, the distance it has travelled is s(t) t(150-t), 1000 where t is measured in seconds from the departure time, and s in metres. What is its speed at the second stop? At what time does it reach the second stop? How far away is the second stop?