Astone dropped into a well is heard to strike the water after 8seconds. find the depth of the well if the velocity of sound is 350m/s

What is the magnitude of the acceleration vector which causes a particle to move from velocity −5i−2j m/s to −6i+ 7j m/s in 8 seconds. answer in m/s.

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?

Which phrase describes the paleo-indians of prehistoric arkansas? a. grew cornb. lived in cliff dwellings c. crafted beautiful potteryd. hunted with stone-tipped spearswhich phrase describes native arkansas from the woodland traditiona. developed widespread agricultureb. hunted mastodon and woolly mammothc.built rectangle-shaped homesd. traded salt with other groups