# Homework Help: Mechanics and vectors problem

1. Mar 20, 2014

### mssnamu

1. The problem statement, all variables and given/known data
An electron, with an initial horizontal velocity of magnitude 3.16 × 109 cm/s, travels into the region between two horizontal metal plates that are electrically charged. In that region, it travels a horizontal distance of 2.42 cm and has a constant downward acceleration of magnitude 2.73 × 1017 cm/s2 due to the charged plates. Find (a) the time required by the electron to travel the 2.42 cm and (b) the vertical distance it travels during that time. Also find the magnitudes of the (c) horizontal and (d) vertical velocity components of the electron as it emerges.

2. Relevant equations
s = ut +0.5at^2

3. The attempt at a solution
s = ut + 0.5at^2
2.42 = 3.16x10^9t +1.365x10^17t^2
t = 7.42

I'm not sure whether what i did was correct and also don't know how to do parts b, c and d.

2. Mar 20, 2014

### paisiello2

You have combined the two different directions for some reason into the same equation. Try to separate the equation for the two directions.