1. To draw attention to mental health and depression, a man in the United States pulled a train from rest. It required a work of 800,000 J. What must be the mass of the train if the man pulls over a distance of 10.0 m with an acceleration of 0.15 m/s?? 2. The bell rings and class is over. You lift your 5.6-kg backpack to a height of 1.1 m, then carry it 100 m to your next class. a. Calculate the work you do on the backpack as you lift it from the ground. b. How much work do you do on the backpack as you carry it at constant speed from the classroom? 3. .A person pulls a crate of mass 12.0 kg with a force of 156! at 23.0 above the horizontal. The crate starts at rest and moves 5.00 m sliding horizontally without friction. a. Find the work done by the person. b. Find the final speed of the crate