At a playground, a 26-kg child sits on a spinning merry-go-round, as shown from above in (Figure 1). The merry-go-round completes one revolution every 6.2 s, and the child sits at a radius of r=1.2m. What is the force of static friction acting on the child?

The of a machine determines its "usefulness." a. input force b. output force c. mechanical advantage

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?

Ryan is examining the energy of the particles in a bar of gold. what is ryan most likely studying?