4-4 On a distant planet, where the gravitational field strength is 10.0 N/kg, a P's heavy plank rests with one end on a scale that reads 350 N. Dr. Urie is holding the plank horizontal by pushing up with a force of 900 N. Dr. Urie is pushing up on the plank exactly 5 meters from the end on the scale. The mass of the plank is: m kg ( + 0.5 kg) The length of the plank is: L = m ( + 0.02 m)