Need to know if my answers are correct (electric field questions)

[skanecfc]

An alpha particle of 3.2 x 10^-19C (to the power -19) accelerates from rest between two oppositely charged plates starting from the +ve plate. The electric field between the plates is uniform and equal to 39000 N/C. The distance between the plates is 4.50 x 10^-3m (to the power -3).

a) calculate the force on the alpha particle.
I put 1.6 x 10^-19 (power -19) x 39000 = 6.24 x 10^-15 (power -15)

b) How much work is done by the electric field in accelerating the particle the full distance between the plates.
I put (6.24 x 10^-15) x (4.50 x 10^-3) = 2.808 x 10^-17.

Are my calculations correct?

Also i must state c) by how much does the alpha particle's KE increase? I know the formula is half MV squared but I am not sure which figures i must use
and d) by how much does the alpha particle's PE change? I know this formula is MGH but again I am not sure which figures to use

 

[Redbelly98]

An alpha particle of 3.2 x 10^-19C (to the power -19) accelerates from rest between two oppositely charged plates starting from the +ve plate. The electric field between the plates is uniform and equal to 39000 N/C. The distance between the plates is 4.50 x 10^-3m (to the power -3).

a) calculate the force on the alpha particle.
I put 1.6 x 10^-19 (power -19) x 39000 = 6.24 x 10^-15 (power -15)

Why 1.6 x 10^-19? Instead, use the charge of an alpha particle, as given in the problem statement.

b) How much work is done by the electric field in accelerating the particle the full distance between the plates.
I put (6.24 x 10^-15) x (4.50 x 10^-3) = 2.808 x 10^-17.

Your method is correct (work equals force times distance), you just need to use the correct value of the force.

Also i must state c) by how much does the alpha particle's KE increase? I know the formula is half MV squared but I am not sure which figures i must use

There is something called the work-energy theorem, if you look that up in your physics textbook it should be helpful here.

and d) by how much does the alpha particle's PE change? I know this formula is MGH but again I am not sure which figures to use

That's for gravitational potential energy, but this is electrical potential energy. However, it would be easier to think in terms of conservation of energy for this problem.