A tennis ball is dropped from 1.71 m above the ground. It rebounds to a height of 0.828m. With what velocity does it hit the ground? The acceleration of gravity is 9.8 m/s2. (Let down be negative.) Answer in units of m/s.

The weights of bags filled by a machine are normally distributed with a standard deviation of 0.05 kilograms and a mean that can be set by the operator. at what level should the mean weight be set if it required that only 1% of the bags weigh less than 9.5 kilograms? round the answer to 2 decimal places.