Long ago, it was believed that maggots came from meat. in the late 1600s, francesco redi hypothesized that maggots came from flies rather than from meat. which of these experimental designs could be used to test redi's hypothesis?

a.) an experiment using covered, unrefrigerated meat
b.) an experiment using uncovered, unrefrigerated meat
c.) an experiment using flies under a bell jar
d.) both a and b

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?