help :)

Hi Guys, can you help me with these three questions, please

1) During a pond hockey game, a puck accelerates from rest at 5.0 m/s^2 over a distance of 80.0 cm. The puck then slides with a constant speed for 4.0 s until it reaches a rough section with causes it to stop in 2.5 s
a ) what is the speed of the object when it reaches the rough section?
b ) At what rate does the object slow down once it reaches the rough section ?

c ) what total distance does the object slide throughout its entire trip ?
d ) what was the average speed of the puck ?


2) The force between two charges Q and q is 3.1 x 10^-8 N when the two charges are separation by 3.0 m. Using this formula F = KQq/R^2 determine the force when the separation R between two charges Q and q is increased from 3.0 m to 4.5 m.

3) Using the formula in Q2, sketch graphs of the relation between :

a) F and R assuming Q, q and K are constant.

b) F and Q assuming K, q and R are constant.

c) The relationship between Q and R, assuming K, q and F are constant.


really i need your help