I only need the answers:

A 0.900 kg hammer is moving horizontally at 6.00 m/s when it strikes a nail and comes to rest after driving it 1.00 cm into a board. (a) Calculate the duration of the impact in seconds. (Enter a number.) 0.286 X s (b) What was the average force in newtons exerted downward on the nail? (Enter a number.) 11.03 X N Submit Answer 0/2.85 Points] DETAILS PREVIOUS ANSWERS OSCOLPHYS2016ACC 8.3.P.023. MY NOTES ASK YOUR TEACHER PRACTICE AN Train cars are coupled together by being bumped into one another. Suppose two loaded train cars are moving toward one another, the first having a mass of 180,000 kg and a velocity of 0.300 m/s, and the second having a mass of 135,000 kg and a velocity of -0.120 m/s. (The minus indicates direction of motion.) What is their final velocity (in m/s)? (Enter a number.) 0.099 x m/s