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A 3.23kg book falls off the top of a 3.01 m bookshelf. What is its kinetic energy right before it hits the ground? ( g= −9.81m/s2 )

Show work please

Ais useful when you need a simple machine to you separate two things. a. lever b. screw c. pulley d. wedge

Suppose a comet has an orbital period of 309.1 years around the sun. what is it’s average distance from the sun?

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?