1. The problem statement, all variables and given/known data A rifle bullet with a mass of 15.5 g traveling toward the right at 262 m/s strikes a large bag of sand and penetrates it to a depth of 24.2 cm. Determine the magnitude and direction of the friction force (assumed constant) that acts on the bullet. 2. Relevant equations F⃗ net=ΣF⃗ =ma⃗, fk=μkN, [itex]\Sigma[/itex]F=n+f+mg=ma 3. The attempt at a solution I have no idea where to start. I tried drawing a force diagram, but I can't figure out how to use my givens all in one equation.