Pls help in these questions Questions : plz plz plz help !!
1. A car travels for 10s at a steady speed of 20m/s along a straight road. The traffic lights ahead change to red, and the car slows down with a constant decelerations, so that it halts after a further 8s.

a) Draw a speed-time graph to represent the car's motion during the 18s described.

b)Use the graph to deduce the car's deceleration as it slows down.

c) Use the graph to deduce how far the car travels during the 18s described.

2.A runner travels 400m in 5s. What is her average speed?

3. How far will a bus travel in 30s at a speed of 15m/s?

4. a RUNNER ACCELERATES FROM REST TO 8.0M/S IN 2.0s. What is the acceleration?

5. A runner accelerates from rest with an acceleration of 4.0m/s^2 for 2.3s. What will her speed be at the end of this time?

6. A car can accelerate at 5.6m/s^2.Starting from rest, how long will it take to reach a speed of 24.0m/s.

7. A bus travels 1425m in 75s.

a)What is its speed?

b)What other piece of information do we need in order to state its velocity?

8. A bus is travelling along a road. It travels a distance of 400m in a time of 25s.

a) Write the equation used to calculate the average speed of the bus.

b)What is the unit of average speed ?

9. The speed-time graph for part of a train journey is a horizontal straight line. what does this tell you about the train's speed, and about its acceleration?