1. A mass that weighs 8 lb stretches a spring 6 inches. The system is acted on by an external force of 8 sin(8t) lb. If the mass is pulled down 3 inches and then released, determine the position of the mass at any time. Determine the first four times at which the velocity of the mass is zero.

Astudy was interested in determining if eating milk chocolate lowered someone's cholesterol levels.ten people's cholesterol was measured. then, each of these individuals were told to eat 100g of milk chocolate every day and to eat as they normally did. after two weeks, their cholesterol levels were measured again. is there evidence to support that their cholesterol levels went down? how should we write the alternative hypothesis? (mud = the population mean difference= before - after)a. ha: mud = 0b. ha: mud > 0c. ha: mud < 0d. ha: mud does not equal 0