12. A 65 kg student pushed off the ground so that she experiences an acceleration of 3.4 m/s2 upwards. (a) Draw a free body diagram of the student. (b) What is the magnitude of the normal force exerted by the Earth? (c) What is the acceleration of the Earth due to the third law pair of the normal force? (mEarth = 5.98 1024 kg) 213. A brick rests on the frictionless rear bed of a van, both initially at rest. The van driver starts the van and it begins moving forward. The brick immediately starts to slide toward the rear of the van. Usimg Netwon's laws analyze the motion of the brick as seen (a) by an observer on the ground. (b) by the van driver