college physics

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i need solutions for all this problems...help please....

1.) an electron moving at a speed of 4x10 power of 6 m/s, shot through a sheet of paper which is 3x10 to power of -5 m thick. the electron energyfrom the sheet with with a speed of 2x10 to the power of 6 m/s. find the

a.) acceleration experienced y the electron in passing through the sheet and
b.) time take by the electron to pass through the assuming that the acceleration of the electron constant...

2.) the velocity of a train changes from 0 to 60 km/hr in 20 seconds assuming that is uniformly accelerated ,what is the acceleration..?

3.) a body is moving with a velocity of 4 m/s . it is then accelerated for 5 seconds at the rate of 2 m/s squared.
a.) find the speed at the end of the fifth second.
b.)find the distance covered during the first and fifth seconds.

4.)a speeding motorist traveling 120km/h passes a stationary police officer. the officer immediately begins pursuit at a constant acceleration of 10.0 km/h/s (note the mixed units). how much time will it take for the police officer to reach the speeder,assuming that the speeder maintains a constant speed? how fast will the police officer be traveling at this time..?

5.) a light plane must reach a speed of 30 m/s for takeoff.how long a runway is needed if the (constant) acceleration is 3.0m/s squared?