F.4 physics questions......help!

Use these equation:
a: s = 1 over 2 (u+v)t
b: v^2 - u^2 = 2as
c: v = u + at
d: s = ut + 1 over 2 at^2

1.A motorcycle accelerates along a straight line from 36 km h^-1 to 90 km h^-1 in 10s. Find the distance travelled by the motorcycle and its acceleration in this peroid.

2.A man on a bicycle speeds upuniformly along a straight line at a rate of 2 ms^-1 to 14 ms^-1 in 5s. Find the displacement of the man.

3.Peter kicks a stationary football to make it accelerate horizontally along a straight line at 20 ms^-2 towards a goalkeeper. The contact time between the football and Peter is 0.3s.

a. Find the horizontal speed of the ball travelling towards the goalkeeper.

b.Assume the football travels horizontally with a constant velocity in the air. If the goal keeper has an arm length of 0.8m, what should the average deceleration of the football be so that he can stop it right in front of his chest?

4.A cyclist moves steadily at 15 ms^-1 along a straight road. The cyclist sees a child running across the road suddenly at 20m ahead. He applies the brake to stop the bicycle. The figure below shows the speed-time graph of the bicycle, where the cyclist sees the child at t=0 and the bicycle stops at t=2s.

The figure:
Bicycle speed starts from 15 ms-1
after 0.5s, bicycle stopping.
after 2.0s, bicycle fully stopped.

A. what is the reaction time of the cyclist?
B. would the bicycle hit the child? Explain your answer.


one more questions:
What is U,S,A,T and V means?

thx for help!!!