1. A crane raises a 200. N weight to a height of 50.0 m in 5.0 seconds. What is the rate at which work is done in watts? 2. A 789 N man does 8.58x103 J of work in 12.3 seconds by running up 3 flights of stairs to a landing vertically above his starting point. Find the power developed by the man and his total vertical displacement. 3. An engine rated at 5.4x104 watts exerts a constant force of 2.5x103 N on a vehicle. Determine the average speed of the vehicle. 4. What is the average power developed by a motor as it lifts a 400. kg mass at a constant speed through a vertical distance of 10.0 m in 8.0 sec? 5. Determine the powers developed by a man who weighs 600. N who climbs a rope at a constant speed of 2.0 m/s. 6. A 500. N girl develops 250 watts of power as she runs up 2 flights of stairs to a landing 5.0 m vertically above her starting point. Calculate the time required for the girl to run up the stairs