A bullet meets wood: accelerations and forces

Hello good people, another complex physic problem I need to get through:

A 9 grams bullet is crossing a block of wood with an initial speed of 250 meters / seconds and a final speed of 150m/s. The block of wood is 7 centimeters.

Determine:
a) the acceleration of the bullet; and
b) the average force that has acted on the bullet


Thanks a lot!

Here's a second one: differenciate the scalar vectors:
mass temperature wind speed
movement distance gravitational acceleration
force volume frequency
voltage weight time

:|

do you ever attend class or have you missed them all?

I missed a couple in the last days and I lost focus a few weeks ago because of my job.
Do you only asnwer with questions ?

Don't you have text book to refer too? All the equations you need should have been given to you, most people don't like to help if you don't show you've at least tried to start doing the work, if you have a problem with something specific point it out.