Eric has a battery operated toy train consisting of 5 train cars. Each car has a mass of 13 g except for the 1st car which has a mass of 8 g. Find the force needed to accelerate the train at 3.0m/s2. **remember, you must convert your answer (grams to kilograms). * 20 N
.2 N
.02 N
none of these

An alpha particle with kinetic energy 12.5 mev makes a collision with lead nucleus, but it is not "aimed" at the center of the lead nucleus, and has an initial nonzero angular momentum (with respect to the stationary lead nucleus) of magnitude l = p0 b, where p0 is the magnitude of the initial momentum of the alpha particle and b=1.40×10−12 m. (assume that the lead nucleus remains stationary and that it may be treated as a point charge. the atomic number of lead is 82. the alpha particle is a helium nucleus, with atomic number 2.) what is the distance of closest approach?