1. Multnomah Falls in Oregon has sheer drop of 165 m. Estimate the change in water temperature caused by this drop.
2. An ‘‘air cushion'' vehicle is designed to traverse terrain while floating on a cushion of air. Air, supplied by a compressor, escapes through the clearing between the ground and the skirt of the vehicle.
If the skirt has a rectangular shape 3 × 9 m, the vehicle mass is 8100 kg and the ground clearance is 3 cm, determine the airflow rate needed to maintain the cushion and the power given by the compressor to the air.
Assume that the air speeds within the cushion are very low.
