1. The diameter of the largest particle that a stream can move is approximately directly proportional to the square of the velocity of the stream. When the velocity is 1/4 mile per hour, the stream can move coarse sand particles about 0.02 inch in diameter. Approximate the velocity required to carry particles 0.12 inch in diameter.
2. The work W required to lift an object varies jointly with the object's mass m and the height h that the object is lifted. The work required to lift a 120-kilogram object 1.8meters is 2116.8 joules. Find the amount of work required to lift a 100-kilogram object 1.5meters.